My big question is how it is going to be handled.
From what I understand all of the new maps and characters for OW2 will be available in the original. Only the new PvE content will be exclusive to OW2, as well as 'engine upgrades'. I don't know exactly what that means but from what I've been able to glean from reading reactions and comments about it, OW2 will basically look nicer (although all of the new designs for characters shown so far are all much uglier that OW1) and perhaps run... smoother or something?
It's all very odd to me. Take this with a grain of salt because, as I said, I don't know much, if anything, about the technical side of things, but using two different versions of the engine, but making all PvP content — maps, characters, cosmetics — available in both, sounds like it will involve making two versions of everything. That seems like a waste of time and resources when they could just... not do a sequel and put the new content in the existing game... like they apparently are doing...
Jeff Kaplan says he doesn't want the playerbase to be split, but if both games use different engines (or different versions of the same engine) how will they manage to avoid that?
From what they've said, it sounds like buying OW2 simply gets you some PvE content. OW1 has seasonal PvE content and none of it is particularly good so that's a poor case for OW2. 'Engine upgrades' is pretty ambiguous, and I have to assume much of it is 'under the hood' stuff, but if this upgrade exists to make the new PvE content possible, as I've seen suggested, then I question if that's even worth it considering people play OW for PvP and will continue to do so with OW2, especially since the e-sports scene has picked up so much and Blizzard absolutely will continue to promote it as the heart of the game.
It feels a bit like a 'have your cake and eat it too' situation. Blizzard wants everyone to feel relaxed that they won't miss out if they skip OW2, but I don't see how it can maintain one cohesive playerbase with two games using different engines but sharing the same content. It's very unlikely I will get OW2, at least not unless it's on sale for about £10 (like I did with OW1), but I'll probably stay a bit informed about it to clear up my understanding of how it's all going to work.
(also, @Satan your friend sounds like they get easily influenced by, I'm assuming, Reddit)