-It's possible we could get news as Early as March, if Sega does decide to show up at SXSW, or whatever online Show they have for the event. New Sonic announcements were announced there, including Sonic Mania and Sonic Forces. though if not, I'd expect it around June of this year, even if E3 is dead forever
-Sonic and Amy being the main characters does sound kind of weird, but it's not the most far off idea. Amy is one of the mainstays of Sonic I would say, along with Tails, Knuckles, and Eggman, as well as Shadow and Metal Sonic (this is taking into account appearances, especially in recent memory). Plus as you mentioned, we've had 2 Sonics and OC as playable, so yes
I also haven't read the IDW Comics myself, but I have heard that Amy in the comics is based off Boom Amy more than the Amy in the mainline games. I'm also gonna assume that while they might tease Sonamy, they of course won't go through with it since they don't want Sonic tied down
-Unused concepts being used in Future projects I think is just something alot of media does, Not just Sega, so I can buy the Hedgehog ancient civilization thing being re-used for something that would do more with the idea. I wonder if they'll give an interpretation of why Sonic has Super Speed, or will they just leave that open to interpretation
-The New Antagonist being based around the Moon and some Japanese folklore also is something I could buy. I know that Sonic 06 had a theme going on with the Eagle motif all around 06, Including with Solaris, the Big bad of the game
-If we are getting elements from Lost World like the Parkour, I do think that is something that is to be excited about, since it shows that Sega is willing to re-use ideas that were present in some of the more critized games, since I know that's been a huge issue with the franchise.
-If this was real, all these New artifacts being introduced into the series might show that they might be trying to phase out the Chaos Emeralds, or at least not make them as prominent, so I wonder if we won't have Super form present like how it was absent in the Story of Colors, Lost world, and Forces. I also know about that whole statement about "Only Male Hedgehogs can go Super" so I wonder if this game is about the Hedgehog kind, if that will come into play or that will be retconned (Hopefully)
-I know there was speculation about there being New writers (the new voice cast thing is kind of new speculation). Pretty much Pontac and Graff seem not to have updates to their work profiles, which might have implied that they were not hired again by Sega to work on Sonic. I know their writing has been heavily critized, and if Sega really is trying to go into another direction, well you know
-I don't buy the leak entirely. I'm open-minded so I'm willing to give this one some thought however
I do wonder how this coincides with the Adventure 1 and 2 remakes though, since that is a Rumor that's been getting more ground and attention, with even some DM's to prominent Sonic youtubers being shared that come from someone that would apparently have info on the games. I know the Official planflet for the Sonic anniversary had "Sonic games in development" as one of the phrases used, with the S added which implies multiple games and not just one.