According to Edmund's twitter, it's because "the game's been out for almost a year." Anyway, Edmund needs to check with the servers.
Hey, I was so confused by this that I went and looked at the Tweet and I'm almost certain that it was simply a misunderstanding. I'm pretty sure he thought you meant the forums were "slow" like 'not a lot of people are on it right now'... not, 'they're physically not working correctly.'
If you just read over the exchange again with that in mind, it will make a lot more sense. I actually misread it the first time and made the same mistake as Edmund, so that's why I thought of it.
Thankfully it seems like they're a bit more stable right now. I noticed Team Meat's blog was also really slow and weird then too, so I'm pretty sure if it affects both, it will get dealt with.
That is all. Hope everyone is doing well!