Your games will be deindexed after ANY changes you will make on the game's page. I have tested it many times - every time when I change anything on the game's page the site removes that game from the index. I guess that behavior is fully automatic.
Viewing post in Reindexing adult NSFW content
No, it is not.
My experience says: send email to support, get request ticket, then create a post in "Question and Support". Moderator (his nick is "No Time To Play") will read it and resend to administrator. And only after all those actions, maybe (maybe!) your games will be reindexed.
This is one of my story: https://itch.io/t/5441904/please-reindex-my-games-i-wait-80-days for an example.
Good luck.