The biggest indicator that the launch of the Ark ships is post ME3 is the fact that they seem to incorporate the Crucible into their designs. Like, no way that wasn't intentional. And it makes sense, given the insane distances these ships are meant to travel.
Ultimately, my biggest concern is going to be what comes AFTER Andromeda. Say the game is amazing (and God do I hope it is, it looks like it could be rad), and sells well. Well, then what?
We're eventually going to have a situation where we have two Mass Effect settings, one in the Milky Way, on in Andromeda. If we stay in Andromeda, we can't go back to the setting of the original trilogy, and if they go back to the Milky Way, everything we build in Andromeda gets left hanging.
I really hope they solve this by bridging both galaxies together or something. Because putting us in a situation where they're both going to be eternally separate is going to cause really big issues with the sustainability of the franchise going forward, which isn't what I want to see happen. I like to think Bioware has accounted for this, but I worry.
Unless this is meant to be the last game in the franchise. Which would make me very, very sad.