So I decided to narrow down what I personally think are the most likely candidates for the next fighter reveal for Pokken Tournament in light of the recent hint (too bad Gallade, Greninja, Swampert, and Krookodile have to be ruled out for now).
Generation 1:
Jigglypuff - I personally don't think Jigglypuff is that likely, but considering Smash Bros is why she is still largely recognized to this day, I won't be too surprised if she's the next reveal.
Arcanine - Popular Pokemon who could use very animalistic attacks to stand out from the other Fire-types currently on the roster, but there is another Pokemon that serves as competition for it. Keep on reading to find out.
Alakazam - Pretty strong candidate as it is viewed as the original Psychic type Pokemon. Combine that with its popularity and the fact it has a Mega Evolution and it seems that Alakazam has a pretty good shot. One major problem that I see with Alakazam is that Gardevoir could already be seen as the special-based Psychic-type attacker in the roster (at least that's what most of her moves are like), and now with Mewtwo in the fray, I can't say Alakazam has a supremely high chance.
Snorlax - Another memorable and popular Pokemon that is a decent candidate (not to mention we still don't have a Normal-type on the roster yet). I could see it being the primary heavy hitter in the current roster - quite slow but can attack with very strong attacks through moves like Body Slam.
Generation 2:
Ampharos - One of the first Electric types Pokemon to receive a Mega Evolution, and a pretty popular and memorable generation II Pokemon. Pikachu might already be the primary Electric type attacker, but I think that doesn't necessarily mean we won't get another Electric type.
Donphan - We still do not have a Ground-type fighter on the current roster, and with the recent hint, I think Donphan is a decent candidate. It's another popular and memorable generation II Pokemon who could stand out with its ramming-style attack, rollouts, and ground moves like Earthquake. While Pokemon like Terrakion, Mamoswine, Tyranitar could serve as competition for sharing some of the moveset possibilities Donphan is capable of, my gut instincts keep telling me Donphan is a strong possibility.
Entei - With Suicune already in the game, I won't be surprised if the other Legendary Beasts will appear as fighters. Remember how I previously said Arcanine would stand out from other the other Fire-type Pokemon currently on the roster through an animalistic like moveset? Well, I think Entei is another candidate for this kind of fighter. Hopefully, if Entei joins the fray, then we should see Raikou join along at some point.
Tyranitar - The big pseudo-legendary of generation II, Tyranitar could really stand out with a quake-style moveset combined with Rock moves, ability to summon a sandstorm, and a Godzilla-like attacks involving biting, scratching, and stomping. Its popularity and fame, further proven with the fact it was one of the first Pokemon to get a Mega, does give it a strong edge in its competition, not to mention we don't have any major Rock-type attackers on the roster currently.
Generation 3
Sceptile - I personally think Sceptile is one of the strongest candidates for the next reveal. It's basically the forerunner for the first Grass-type to become a full-fledged playable fighter thanks to all that it has going for it (starter Pokemon, Mega Evolution, and the fact it's soon going to have major importance in the Pokemon anime as Sawyer's, Ash's main Kalos rival, signature Pokemon). With raptor-style attacks added to the mix, no doubt it would be unique. It is debatable if we will actually see more than one from a regional starter trio be represented on the roster though. Well, if Sceptile does make it in, then I hope Swampert will eventually join in since it would be quite unfair to have two of the trio represented while excluding only one.
Salamence - One of the strongest candidates for the first true Dragon-type rep right now. I'd say Dragonite has a better since its more iconic for being the original Dragon-type, but with the recent hint, Dragonite can be scratched out for the next reveal. Salamence is an iconic and popular generation III Pokemon known for being one of Hoenn's pseudo-legendaries, and he also got a Mega in the most recent games. He would definitely have a very Dragon-esque moveset and perhaps take advantage of his diverse move pool as well.
Generation 4
Luxray - I'll admit this is more of a hopeful candidate for me, but Luxray is popular and has a relatively major role in the anime ( arguably Clemont's main Pokemon). He would basically be the Electric-type version of Arcanine or Entei where he would use very animalistic attacks, but instead of fire, he would use electricity.
Mamoswine - Another decent candidate for the first Ground-type rep. In addition to using lots of ice attacks, I can see many of its attacks involving ramming and quake-style moves similar to Donphan.
Generation 5
Galvantula - One of the first Generation 5 Pokemon revealed, with some solid popularity and support on its back along with the fact no Bug-types currently represented on the roster, I can't help but think Galvantula is one of the best candidates for the first Bug-type to be revealed next Thursday. It would make for a really unique fighter with its bug attacks combined with spider attacks and electricity (Electroweb anyone?).
Bisharp - I'll admit this is another hopeful candidate, but he's fairly popular, has a Steel-typing that isn't represented on the roster at the moment, and has unique potential with a dual-yielding moveset along with the possibility of an added Assist moveset where it could summon Pawniards to attack at will. Gallade is definitely his biggest competition due to a relatively similar design, similar moveset potential, higher popularity, and the fact Gallade has a Mega Evolution while Bisharp doesn't, but now that Gallade is ruled out with the hint, Bisharp could (not entirely) have a chance to make it in before Gallade.
Hydreigon - This is another candidate for the true Dragon type rep at the moment. Hydreigon would definitely attack as a true Dragon terror, attacking with ferocious bites and special-based attacks like Dragon Pulse, Dark Pulse, and Flamethrower (perhaps even executing these attacks three times at once thanks to its three heads). Dragonite and Salamence are competitors since they can be similar in moveset potential, but Hydreigon does have the advantage of being a Generation V Pokemon, so there's that.
Terrakion - Another strong candidate for the ramming kind of fighter, not to mention he could also use Rock-type attacks and a quake-style moveset. Some Pokemon already mentioned do serve as competition for similar moveset potential though.
Generation 6
Noivern - One of the first generation 6 Pokemon revealed, has solid popularity, and unique moveset potential with a sound-based moveset, I think Noivern has a decent shot for the first generation 6 Pokemon to become a full-fledged fighter at this point in light of the recent hint. It does have to compete with Exploud, Jigglypuff, and Wigglytuff with the sound-based moveset though, not to mention even Pokemon like Goodra or Hyreigon could serve as competition for the possibility of special-based Dragon-type moveset.
These are the Pokemon that I feel the most confident about in regards to who will be revealed on December 10. It's also possible that none of the Pokemon that I listed will be revealed on that day, but hey, I'm just speculating. What do you think are the strongest candidates for the December 10th reveal at this point?