Has something happened to the forum? Most of the posts appear to be old ones?

Where are you seeing this? When I visit https://our.umbraco.com/forum/ I see posts from today. The home page has posts from today too

There are a couple of new ones but most of them are very old

Happens when a spammer comes in and posts to old threads. You don't see the spam posts but the threads get pushed to the top again. Sucks. Also our forum isn't smart enough to deal with it. Can't wait to delete the old forum next year! (After migrating to something more appropriate of course)

yes very annoying