I'm still looking at my bank account and weighing the pros and cons.

Tumblr going under would be a devastating loss to fandom history. Unfortunately, I'm pretty sure we've been seeing bits of that for years; there are tons of fics on AO3 that will link to specific Tumblr posts, but when I click the link for more context, the post is gone. Either someone changed their Tumblr handle (and I only learned recently that I can just plug the new handle into the old address for it to go right again), or they deleted their blog entirely, or something else entirely.