I wouldn't switch until you get the invite to order. Once you get that you should be able to pick a new dealer and then also order the truck. I would imagine if you switch now you would for sure be behind the first 25 prioritized reservations.
It should be based on reservation timing but it is clearly based on what stat you live in. I am in TX (where 17% of F150s are sold) and most dealers are getting almost no trucks this year. Meanwhile some other states are getting lots of trucks and folks who reserved in the summer can order. People should complain to ford and take to social media in my opinion.It is not transparent. It might even be a "deceptive trade practice" defined under law as "a material representation, omission or practice that is likely to mislead a consumer acting reasonably in the circumstances."
I moved BACK to the original dealership Ford set me up with. I am now #15.
They will get two this year.