Based on a n=1 sample anecdata: When they froze premium subscriptions, I joined their waitlist to be informed when they would offer them again, and yesterday I was presented with a message inviting me to subscribe to plus.
Not sure if they've opened the floodgates or if they're doing a phased opening, but I have also not seen any articles covering this development, so leaving it out here for your info. Has anybody else experienced this?