most melee DPS have positionals to make it harder to move around freely.
casters have cast bars to make it harder to move around freely.

melee have combos, and casters usually dont.

physical ranged are a weird tank like style, with more stuff to keep track of.

So if they make BLU a tank, they should pick a different style, and positionals would be a bit of an issues, unless they are OT, and with the "no tank stance" style of tanking, it would be unique, but a hindrance to groups/meta.
This leaves the caster style, limited by cast bars.

The "rotation" would be simplified, like how tanks are a simplified version of phsyical ranged atm. (Or a lack of rotation, in order to not mimic current styled tanks)