This guy... telling ya right now, cuz why not.
(Also, another spoiler below the picture)

In Fiercy Forces he will be named: Mecha Golden Toy Sonic

And he's not gonna be originally from FNaS4 Scrapped/SHPP Aftermath version...

But!

In Fiercy Forces he will be from FNaS6...

Why I have made such a decision?

Because, for me he suits more there, still as a FNaS 2/6 model
(2017/2022) timeline Character, rather than "jokingly come out of nowhere"
non-looking Nightmarish Animatronic.

He's more like a Mediocre Melodies Character from FNaF6.
(Mecha Golden Toy Sonic is a "Joke" Secondary Character in
FNaS6 Fiercy Forces version and that will be his own origin)

Overall, Mecha Golden Toy Sonic is a reference to:
Golden Toy Freddy and Nedd Bear from FNaF series.

(What I think is that, now FNaS6 All-Stars exist.
And it would even make more sense for me to build a replacement
of Toy Sonic after the events of FNaS2 in FNaS6 or something like that...
It is just only my opinion)