I'm currently waiting to hear back from someone who told me they would contact me in 1 week. It's been FOUR.
Mirthal shouldn't trust his publisher anymore if they got him in this situation and he shouldn't trust Steam because clearly the 3–5 business days line is horseshit.
This whole debacle is generating pages of angry comments per day and, while they may get buried, it's not like they're going to go away. I don't really see the how much monetary difference there would be between a monthslong bungled release or a release on Itch followed by one on Steam.
I don't buy the conspiratorial line cause this is just too embarrassing. Maybe for the delays since Jan, but not the November release delays. Imo the only way this could get worse is if the game gets reviewd bombed, which doesn't seem out of the question at all, or if it's delayed so long that it misses the holiday rush.
Release it now so you can't be accused of the worst. Make an apologetic tweet, release on Itch, and people will forgive. The people who would only buy on Steam will do so anyway on release. Avoid the review consequences. Trust that your game is good and will bring its own long lasting interest. Clearly it has proven so already.