> Calimero is a desktop manager which, besides some fancy things as flying icons, allow the user to download images directly from site like Picsum, Pexels, Reddit (every subreddit) and Danbooru. I suspect their automated abuse-detection system flagged it as potential malware/ransomware due to raw heuristics, and the support staff simply didn't bother to actually look at the source code.
I sounds like it is violating ToS of those sites, at least Reddit. Have you confirmed that tool is compliant or encourages to be compliant? For private repo, it is fine since they don't know if you actually have a right, but public tools cause DMCA issues. Hard to say.