The "board" in your "simple image board" example implies some form of non-image content that displays multiple images in a forum or gallery arrangement, optimally with some form of search, such as via HTML-CSS-JS pages. The "moderation" capability in any presentation medium like this is not impacted at all by IPFS -- it's merely a file distribution and storage backend that can be linked to, from this other hyperlinked content-display medium. This would be like expecting "content moderation" features built into NTFS just because you want to build a web content platform on Azure. This moderation is properly handled by the board content flagging and social tools, not in the file system backend (IPFS) directly.
You can utilize multihash blacklist tools on both your IPFS nodes and content-display moderation code, but you can't "moderate" anyone else's IPFS node storage in this manner.