Not sure if I understand correctly, but it seems that 196 may have a home for what you're maybe describing
I'd recommend https://lemmy.world/c/general it's a community for general discussion and people seem to post whatever with no problem.
Hi there! Looks like you linked to a Lemmy community using a URL instead of its name, which doesn't work well for people on different instances. Try fixing it like this: !general@lemmy.world
At least in KBin/Mbin instances there are magazines called "Random" by default that include an non-taghed microblog posts and threads.
It's also effectively unusable and largely full of spam, as a result. Blocking that magazine makes browsing the All feed actually functionable.
I don't have it blocked and have not noticed a whole lot coming out of it. I actually thought most of it seems to be posts that somehow did not get posted to intended groups and wound up there. Like maybe the tags messed up.
Do non-Lemmy communities count? Or are you just looking for places on Lemmy?
!196@lemmy.blahaj.zone is good one really
Basically post whatever
The rule of the community is post before you leave