Anecdata: Ordered my Mac mini M4 Pro (48GB) on April 1. Was told it wouldn't be available until June 4 but it just came in yesterday—a full month early. So I think there is an "underpromise; overdeliver" thing happening with current orders. Will be curious to see what happens with the Mini M5 release this year.
Put in an order for 64GM Mac Mini late March. I'm feeling luck now having pulled the trigger when I did.