Honestly, I think they'll skip over the "how" of Matt's survival and leave that for the audience to imagine their headcanons as to how it happened. Netflix shows have had a habit of glossing over plot details from previous seasons if they're not relevant to the immediate story:
The Defenders was guilty of somewhat ignoring the aftermath of Matt's identity reveal to Karen (
Charlie Cox and Deborah Ann Woll weren't really happy that this got mostly glossed over), although understandably, there just wasn't room to deal with that in
The Defenders without slowing down the story. Same reason we don't see whatever legal chicanery Foggy did to get Luke out of jail: it's interesting, yes, but it doesn't bear weight on the immediate plot of
The Defenders, so not relevant. And the same goes here for Midland Circle: Matt survived, yes. But the "how" is irrelevant because it will bear no weight on the immediate conflict between Fisk and Nelson & Murdock. (Plus, if they don't show the "how" of Matt's survival, they can also leave it ambiguous whether Elektra survived or not)
It'll be interesting to see how Matt gets his law career restarted. And what's happening to his apartment. (Personally, I imagine that they'll keep Matt in his big corner apartment, simply because it's too iconic to get rid of, with Foggy and Karen keeping up appearances to make it look like Matt is still alive as long as possible so that his disappearance doesnt coincide so directly with Daredevils disappearance. Of course, Matt did tell Karen he got a great deal on the apartment because of the billboard across the street, so maybe the apartment still be available for him for the same reason he got it in the first place: the billboard is a nasty distraction for sighted people. Then again, Fisk did blow up Matt's apartment in the original "Born Again" story, but time will tell if that's the case).