And if so, are there any plans of replacing it for searching similar images any time soon?

We don't run iqdb.org. That is someone else.

From what I've read online, they lost all their site files because of the bullshit caused by that Canadian child protection group's bot uploading child porn to IQDB's servers. This is by the people behind saucenao, but it explains what was going on, because the bot did it to them too:

saucenao.blogspot.com/2021/04/recent-events.html

Apparently IQDB's host scanned their site's files with Microsoft's PhotoDNA while the images the bot uploaded were still in the cache files. Since this counted as a positive result for child porn being on the site, the host then killed their site entirely and are refusing to give them a copy of their files. Last I saw, their host was refusing to even respond to them further.

If they do come back, it'll probably be a while because of that.

As a side note, apparently the bot's still doing it. saucenao blocked searches from Amazon Web Services, which is what the bot's running on, to prevent further problems.

Jesus Christ, how horrifying. And oddly hilarious, in the most depressing way possible.

Thanks for the information.