Sakurai does not consider echo fighters as newcomers considering he literally put them next to the fighter they based off and doesn't add a new number. He also even gave people the option for them to replace the fighter on the CSS as a toggle. His statement is true considering he only introduced 4 "newcomers" (not echoes) and said there's only a few left to reveal. Sakurai clearly said don't expect many newcomers because he caught a lot of criticism for adding Lucina/Dark Pit/ Dr. Mario even though all 3 have gameplay differences. People still disliked the idea of those 3 and I'm sure Sakurai is covering his bases so people don't criticize him again.(People still will). Think of it like this; if only 4 characters were new while 12 were echo fighters, people would be in their feelings. Echoes are meant to pad the roster like how Melee did clones. Melee still caught criticism for having Melee clones as well. It's never something that will be universally agreed to as good. This is clearly dessert for Ultimate though IMO.
I for one is not that much of a Nintendo fan to be blunt. I despise Mario games other than some spinoffs, I found Zelda very lacking until BoTW. Never played Metroid, FE, many others. I heavily prefer Square-Enix and other RPG's than Xenoblade, loss interest in Pokémon 2 yrs ago (didn't even finish Ultra Moon.) This is why I never particularly was against any Nintendo character from being included into Smash (I was neither am against or for them). I was somewhat supportive of the cause. You would see me support more third parties such as Sora, Geno, Bomberman, Banjo, Rayman, Eggman. You see, none of these characters have any chance of being an echo unless Sakurai would really want to disappoint not to mention the respective company outright rejecting echolocation.
I expect for their to be an equal number of newcomers and echo fighters. I can see him adding a slightly more echoe fighters than newcomers. I could be wrong.
Personally I'm fine with echo fighters as long as they were identical to the character as it's really hard for me to use an inferior version (hello Dark Pit and yes Dr. Mario even though he's not an echo) for me. I will never use Samus again because Dark Samus actually has a normal roll along with a dash attack that combo into her other moves while Samus does not. Chrom will likely outclass Roy (considering he's the Lucina version of Roy with not having a backwards (flawed) tipper mechanic) unless his recovery is much worse than Roy. Roy sword mechanic does not fit a sword especially since they made his sourspots utter garbage (many times there have been where Roy should have KO'ed me but didn't because of inverse tipper). For the casuals out there that might be triggered off this; please note that just because I said a character may be inferior does not mean they will be bad. Don't be replying back talking about why Roy/Samus/ Dr. Mario is good when I never actually said they were garbage.(although Samus is looking bad/worse than Smash4 considering she loss all of her Combo options so far in the demo). Hopefully she gets massively retooled at by the balance team.
To end; I am not against echo fighters, in fact I will say I am slightly more supportive of them after Chrom/Samus while being disappointed that some of these may very well almost completely outclass their original. I don't know how I feel about the last statement either. I should be happy that there's s better Samus right??? I also should be happy there's Chrom who's is nearly identical to Roy without being held back by his mechanic along with not being in a defensive game.
Casuals ought be happy about echoes considering they don't need to be concerned or care about the intricacies of META and competitive like me; another advantage of being Casual. ;-;
I care much more about character interactions and their options rather than the character themselves. I have little tolerance to play characters that subpar in the meta regardless of who. If snake ends up being average, I will sadly ignore him for the most part. Top Tier/ High Tier is my motto of course I will never question others ideologies either.