Didn't Ultra Magnus already come with those alternate faces anyway? I don't have mine out so I can't check. And of course now that I'm trying to google it, I can't find any clear images Haha
And a couple of swappable faces (that the original release had - or at least had something that used the same fixing/hole) is different to a whole new extra that you won't be able to buy separately, basically leaving that hole in the original release Primal's arm for no reason. It feels strange for TT to go to the trouble of moulding a peg hole for a possible future repaint, when all they would have to do is "remold" an alternate panel if they decide to release a repaint/retool.
Seems like a weird move if that's what TT end up doing.
The new eyes that came with Delta Magnus are the rectangular and bug-eyed ones:
So old stock eyes:
New eyes that came with Delta:
It makes them money, because a collector will be compelled to buy the repaint/new figure. Kind of like how people just bought Soundblaster to get Ratbat.
Of course, it's all just speculation on my part.