Always bit disappointed how anybody could ever imagine Archer and Future Guy being one and the same to be honest.
Future Guy uses genetic engineering on the Suliban, and generally pollutes the 22nd Century with stealth (read: cloaking device) technology. Archer like everyone else on Trek is a scientist of course. But face it, he's a glorified test-pilot and barely a warp engineer at best, mostly off of his Father's genius. I don't think redesigning a species is his bag. He's also a moralising boy scout. Even when committing piracy, he's still weighing heavily in favour of good deeds versus bad.
Future Guy's agenda at various points involved destabilising the Klingon Empire, and ensuring the Enterprise NX-01's mission ended prematurely. Not sure what would link both of these to Archer. The latter's a possibility, because - if successful - he'd be at home when the Xindi probe arrives... but what about causing First Contact with the Klingons? Or other crimes we presume the Suliban did with their tech advantages that came from the future?
Reveal who the guy is, and use him as a way the Discovery try to get home from the 28th Century... (in theory)
I can see how that could work. And have zero to do with Archer, unless it diverts them to the 2150s along the way.