Honestly, unless he has the worst camp of his life, Washington will be on the team. I don't think they even bother signing Washington if they think he will be cut. Dobson has 0% chance of making this team, but to those thinking Mitchell will definitely make it, I think Washington has a better chance. Let's not forget, Mitchell was a FOURTH round pick. Also Lucien has no chance of making the team. Both Mitchell and Lucien probably get cut and added to the practice squad. Though that is a very risky route to go, especially if they have great camps, other teams will be watching.
I think it will be
Edelman
Amendola
Hogan
Washington
Martin
Slater
Mitchell and Lucien on the practice squad, Dobson to Dairy Queen working the drive through window.
Of course, there is always a caveat or two, lots of IF's. IF Mitchell and Lucien are incredible in camp, and BB is afraid to lose them, he's been known to be cut throat and cut a veteran so Hogan, Martin or Washington could be cut. What if De'Runnya Wilson is a beast in camp, do the Pats keep him as a TE and cut a vet TE ? LOTS of IFs, but if things happen as I suspect they do, I think those 6 vets are your receivers. I REALLY want Mitchell, Lucien and even Wilson to make the team, but they would really need to knock BB's (and Brady's) socks off to make the starting 53.
When have we had this many receivers that could be contributors ? It really is a GOOD problem to have that there will be some tough choices. I will be definitely concentrating on the WR/TE competition, should be very interesting.