It looks like it's going to be real.
https://www.reuters.com/world/europe/finland-make-decision-nato-membership-coming-weeks-2022-04-13/The majority of the Finns also support this move.
Finland having the courage to send arms to Ukraine already was pointing for the move to join NATO.
On Sweden things aren't as clear yet.
Putin can claim that getting a piece of Ukraine deserves the price of seeing Finland and Sweden joining NATO, but he will get the latter without having the former.
I'm still astonished as how a successful dictator could take this stupid decision.
Some say that his isolation, caused from his fear to get Sars 2 (the big tables are proportional to his fear), can explain his paranoia and this absolute blunder.
Interesting, however, as the article mentions, there isn't a timetable on when that will happen. Recent polls show that 68% are in favour of joining NATO, while only 12% are against. What about the rest 20%? On top of that, we should also take into account the accuracy of the poll, which is something unknown, at least till more of them rollout.
Putin had warned about Finland since the start of the invasion, however, his army is now devastated, thus, I highly doubt he'd make another threat a reality.