"No AI" is just a tag someone made. Just like the Horny-Eyeballs tag and the thousands of other tags. This has nothing to do with the AI generation disclosure section of the project page, which is still unavailable in search.
Horny Eyeballs. Hah. ;-)
But seriously, the way the ai disclosure currently works for users to filter with, is with tags. Read the announcement. https://itch.io/t/4309690/generative-ai-disclosure-tagging
This here is an automatic tag: https://itch.io/games/tag-ai-generated-graphics It does not appear on the tag list on such games. Unless someone chose it manually.
So yes, no-ai was used before and very likely currently by developers. But it is also given automatically by the disclosure. And the way I understand it, it should only be visible if manually chosen.