I agree that some sort of money making might help the situation. $ 5 would be enough to discourage a lot of spam, scam and joke projects that keep up the time of staff as a side effect. Nothing against a good joke project, but if it provokes mails to support or takes time away from staff to get indexed or removed from index, that can pile up.
For the crosslinking of socials/release platform, unless prohibited or there are reasons, it should always be done. For marketing and search engine optimisation alone. Someone might stumble upon one of the socials but does not like that platform too much, but would prefere one of the other places.
But, no, there should not be a direct linkage for getting indexed, just because you link to Itch from Patreon. But having natural traffic from Patreon to Itch from people curious about your Itch page might speed up indexing, as it is said that projects with more natural external traffic might be prioritised. It can also calm down anyone concerned about you being a possible impostor. They might get some warning about an unsigned exe or even a false positive from their scanners. What to do in such a case? Ask the suspected impostor? ;-)