As described in How many Marvel Earths (Universes) are there?, there used to be lots of Marvel universes, but Secret Wars combined them all into one (aside from the cinematic universes, which were untouched and are largely ignored by the comics). From KutuluMike's answer:
Technically, as of right now, there are very few Marvel universes. The recently released Secret Wars (the 2015 one, not to be confused with the one from 1984) event has effectively erased all numbered comic-book universes from existence, leaving only Battleworld. Once that event series is over, in theory there will only be 1 comics universe.
Is this singular remaining comics universe (the new "mainstream" universe) still referred to as Earth-616, despite being the only-ish universe still around? Or is that designation no longer used and it's called something else?
I'm mostly interested in in-universe designations, but would welcome out-of-universe designations as supplementary information.