Glad you like Eternum, now you play the waiting game with us

Dev cycles have varied between something like 5 and 7 1/2 months with the latest updates having taken longest, but we definitely expect another update this year and the dev has said they will try to keep the update cycle at or below the last ones.
Theories for our MC's possible demise range from: he aint dying at all (perhaps using his powers on earth for the first time) or him dropping into limbo with maybe Idriel or be an NPC for a while as you suggested yourself.
Calypso's possible involvement was also discussed, with the one caveat that she had already mentioned she tried making a portal to earth prior to the current events and it did not work. May change however. There was a theory that MC may drag Calypso to earth herself, having her stranded there.
And just to clarify, you mentioned both "real life" and "server" and that may just be because the terms just come up, but at the beginning of the last update we got the reveal (which was already heavily hinted at) that
Eternum worlds are not servers but actual other realms and earth is just one of them, nothing like real life or anything. Annieway, great to have you, but now you must wait. First set of sneak peek to the next update dropped
here and progress was put at 20% currently iirc.
Cheers =)