I have been to Finland a couple times, because I have family there. My Finn relatives all lament that they didn't join NATO after the fall of the USSR when they had a brief window where they could have done so. I don't know if that's a general sentiment or just them. My sense is that an attack on Finland would be another level from an attack on any former Soviet republic. Finland is part of the club of fully civilized nations. It's really shitty to say it, but I think we tend to care a lot more about people we see as our peers. Ukraine just isn't a peer state in way Finland is.
True about the perception of "peers", for better or worse. What incentive does Finland have to not join NATO if Putin has just demonstrated that membership is irrelevant and proven that NATO only has your back forrealzies if you're a member state? Neither does Finland's long history of Russian incursions do Putin any favors. I think Putin's off the deep end. This could end very, very poorly. I think the Finland/Sweden threats are probably hollow, but the uncertainty is killing me.