I don't think there's the slightest chance of an @operamail.com address being available beyond the middle of next year. I'm happy to move away as despite the effort involved there are advantages. Moving away gives users the chance to renew or delete user accounts, logins, passwords and all the rest. The move away should reduce spam emails to a trickle once spam arrives at a defunct address. The vast majority of the spam email I receive is a consequence of hacks to Adobe and the like in the early 2010s. I'm looking forward to all this idiot crap slamming into a dead-end come June 21.
Even though I have 500+ operamail related addresses to move over to another address I'm finding that the process of updating logins has been worth the effort. There are plenty of usernames I don't need any more. And it's interesting to see how many companies take GDPR seriously, You know they do when you find they've deleted your user account information after a year or so without a log-in. And which other "service providers" can't even deal with a change in email address! I'll be taking my leave of these.
There's no way I'm going to feel aggrieved for the loss of a particular email address. It's inconvenient but so is much of life. I'd be more worried about the demolition of an ancient building but at the end of the day an email address is simply an electronic tag of slight consequence.
If I'm correct in suspecting that this is one of many overtures in future cyber hostilities to come then that only increases the incentive to move on from all things Opera related including the browser. I assume the new owners don't give two hoots for the preoccupations of Western users and that their attention is and will be entirely focused on the home market. Opera was good while it lasted, now is the time to move on.