...with some long speed types like Janis, Davis & Dupre.
I would hardly be shocked if the WR group was Nelson, Adams, Cobb, Allison and Yancey, with 2 of the 3 you noted not making the roster.
In fact, I would not be surprised if none of those 3 make the roster, given the 3 TEs are likely to get a fair number of snaps and Montgomery has position flexibility in moving to the slot in a pinch.
I wouldn't pen in Allison and Yancey at this stage since the #4 and #5 spots should be competitive, but Allison did move ahead Janis and Davis last year and Yancey's draft status gives him an edge over Dupre.
Yancey's size and strength (21 lifts), along with what looks to me like long speed in his 4.53 time, might qualify him for a gunner job which would make Janis expendable.
In any event, I would expect the receiver group to be 5 or 6, but not 7, and I'm leaning toward 5. When you get to those bottom 8 roster spots that don't make the game day roster, if the basic depth requirements have been filled in the top 45, the remaining spots can come down to perceived potential with less regard to position.