When I check with a non-logged in browser, no warning. So apparently there is an IP-based filter
You ip does not change by using a non-logged in browser. But if you are logged in, why should the system quarantine the stuff you uploaded yourself from you.
Support will not answer within hours, most of the time. They typically do not answer at all.
When the mod, who is not itch staff, talks about categories, the message board categories of this very community are meant. The subsections have a rule section what to post and what not and how to post certain things.
There is nothing you can do but wait, while itch staff investigates whatever caused the flagging of your page. If it were infringement, it probably would not be quarantine, but file suspension or mere deindexing, while it were investigated.
You might know or not know, but there are many accounts hacked each week. Very likely hacked by downloading things from itch. It was evident from those hacked accounts posting more malware each day. There is this psa thread about try my game on discord scams explaining part of the problems. Anyways, itch does fight those scammers, but it is hard, since it is free to upload things on itch. So their automated systems either have some false positives or the number of visible malware increases a lot.
So a likely scenario might be, that your game executeables triggered a false positive on a malware scanner. There are game engines that notoriously give false positives now and then. Including godot and renpy and I believe gamemaker and likely many others. Especially exe packing is very bad in that regard. I see your windows file is an exe and not an archieve. I am too lazy to try it, but I would bet that this exe triggers several scanners. Godot packed exes are utter garbage in my opinion, because they trigger scanners so very often.