I think that tamping down on post count is a valid concern for communities with high traffic. Too many posts can squeeze out other posts, not let them be seen.
But that's really not the case for !imageai@sh.itjust.works now. Over the past four days, we're averaging (checks) 7.5 images a day. That's not a whole lot of traffic.
When it gets to the point that there's too much of a firehose to manage, then I think that stuff like placing restrictions on images to try to get more of the very best visible or limiting the amount of content that people can post or splitting out into more-specific communities might make more sense. But right now, there's nowhere near too much traffic for me, at least, to handle.
EDIT: Like, if there were a way to get people posting more content rather than less, I'd rather have that; I think that that's a larger concern.
EIDT2: On /r/AIArt on Reddit, they just got that many images submitted in less than the last hour.