It was apparently due to targeted action from AHS.

According to this Gab post:

Loki88 is apparently bragging about getting saidit banned on Reddit's r/AHS... go figure. Most of the drama is going on at r/saiditnet, which is saidit's official subreddit (seems ironic, but okay). It's pretty much a sludge fest between the Reddidiots who think I shut down saidit just because I'm trans, and the Reddidiots who actually shut down saidit and want r/saiditnet banned too. I don't think I'll make a Reddit account, since I'd probably get banned instantly, and anything that needs to be said can be done from the safety of Gab. But I'll try to check r/saiditnet every so often and make updates on what's going on.

And also:

I was able to remove the death threat SaidIt was allegedly taken down for. I banned the user (one of Loki's iron right alts), but it's only a matter of time until he makes another account — and the sever host will be more than happy to ban us again... but it's up for now.

I'm guessing that the redirection was a temp fix while the admins worked to get the hosted site back online.

Honestly, I'm not a big Saidit person. It seems like they get less traffic and interaction than communities.win. Plus they are on a very pozzed server host that will make saidit susceptible to this sort of thing until they move to a different provider. (Which is why c/IP2Always is here for example.) For those who frequent Saidit, what are the active communities that bring you back there?