Will Lawrence sit? Will Wilson sit? Of course not. You don't go after QBs of this caliber to sit behind a mediocre, at best, 1 year rental vet.
I'm sure Dalton is thinking, "they lied to me, I'm not really QB1." If Dalton does start at the beginning of the season, I'd give it about 2 offensive series before the fans are loudly clamoring for Fields. Fields going to put more asses in the seats once you're allowed to put more asses in the seats.
If training camp goes on as normal and there is time to assess things, I don't see the Bears starting Dalton over Fields at any point.