Thanks for answer!
"tldr; not easy to revoke access to something you have already on your disk, and if you don't include some sort of drm there's nothing stopping anyone from sharing it with friends or post it somewhere."
I was trying to say the acces from download it again on itch io. I know that when people are already with it on they hard disk, there's no way to block their acces(and I will never want to do that too).
But yes, you are right. I will don't care about this anymore, I will do my job and let people free if they want or not to contribute many times as he/she wants ^^
Thanks for your time! :)