Thanks for the additional use case information Alessio - I'll bring these use cases back to the devs.
Your post api-hook solution for FindPlayers() - is clever. I was going to suggest using presence in a filter - but doing it in the post-hook likely performs better. Good solve.
The "Disable matchmaking for players after XX days" is a nightly job - so it gets run at a particular time each night. I'll have the test team review it - but that's likely what you're seeing... Agreed that that isn't a solution for your use case.
I still don't think I understand the use case for the matchmaking call where you supply specific profileIds to ignore though?
Paul.