Firstly, most of this post is just repeating pretty much what I said, but as though it's a different opinion, so not sure what you're saying there.
My point is, looking at this with neutral eyes (even though I'm very much a 616 Skrull fan) to the GA, the 616 look wouldn't bear any significance at all. You say the Ultimate look isn't much 'cooler' than the 616 look, but you don't seem to realise that the only reason the 616 look is cooler to us is that we've been used to it for years. It feels iconic. To the GA, one look is as good as the other, so then choosing reason like I mentioned, that is, potential scientific plausibility, variety of having a new race that ISN'T humanoid (which we haven't seen in the MCU thus far anyway) and also the more engaging narrative and dramatic implications of the shape shifters 'reveal' where the change in appearance is more stark and obvious, rather than a different colour with a Robert Redford chin.
Seriously, this isn't about forcing you to like Ultimate version so much as at least accept the possible reasons why it would be chosen over the 616.
Or use my eyes and ability for critical assessment? They both have exactly the same eyes and the ridged chins. Seriously, I think you need to take a step back from this and try and look at things objectively, I think your fan love of 616 Skrulls is blindsiding you a little.