I don't know about the delays part; it would be really nice if there were some transparency there (hence my question a couple days ago about putting that info in the spreadsheet here). I ordered from Granger, and my truck seems to be taking a bit to get on the schedule, so I fear this
could be true. Probably other on here more knowledgeable than me about that. Seems like it would make more sense to make sure the dealers selling lots more than others have stock to sell because that's going to make Stellantis more in the end though. But IDK.
If priority service means scheduling you ahead of others that didn't buy their truck from the local dealer for service/warranty repairs/etc. that could be true. I've chosen not to worry too much about that personally though and will try to escalate if I have warranty issues that aren't getting resolved. There are several local dealers for me as well though, so that makes it a bit less concerning than if there were only one.
I don't trust anything a car salesperson tells me unless I can verify it somewhere else. There is a stereotype about car salesman for a good reason.