I doubt the transfer would go through before this incident resolves, to be honest.
This could conceivably end up being bad for Spiderman, since it's an offer targeted directly at them, maybe some base suspicion is warranted. It's possible there's multiple results for them going, some of which may be worse than what we're told will occur if they don't. However, it doesn't seem to me as if the downsides of the aliens achieving victory are in any way worth the guarantee of personal safety (which will pretty much always be a risk in this profession). The joint victory becoming a mechanical possibility suffers a very significant setback, there is potential for loss of life, and the townsfolk (by extension the Superheroes) lose social allies.
Of course, Hello World's prophecy could have already come true and Spiderman wants a bad outcome to occur, I don't think this is likely but it's always a possibility.
I hope there's still time to save them, but whatever happens tonight, it benefits everyone to jail Doc tomorrow, so we have that to look forward to.