The way itch.io's system works is weird in general. When you publish a game, there is a checkbox, saying "Make game visible." If you don't check that box, your game that you published is not visible. Ummmmm, so when I publish a book, if the publisher don't put it on the shelves, if they don't even put it in a search engine, that doesn't seem very published to me.  We call these things "Drafts."

And yes, writing a long review that nobody could see is kinda off.

I just found out about this now and while I understand what you're trying to do here, naming an action a "review" implies that it behaves like a "review" on other common platforms. If you're not going to consider making reviews public, then PLEASE rename "review" to "give feedback". The current wording just made me assume that devs would be notified of a review, but it would still be visibile to all.

I personally find public reviews to be very useful before I buy a game, and the ones I've seen on itch.io have been very helpful to me (as well as kind to the developer). I also left some reviews to help others out but realised only now that no one would have seen them. That is an issue - how you address it, is your decision.