At least for some stuff which is easier to complete.
This may sound silly, but it's actually something that worked decently in DCUO...
If you don't have a healer, everyone gets a nice "Regen" buff
If you don't have a tank, everyone gets a defense bonus...
If you don't have a dps everyone gets a damage bonus... etc.
It would make for faster queues for dungeons that nobody will want to do anymore like WP and AK once the majority of players have moved beyond level 70 Item level so that newer players can get leveled up in gear too.
Or do you think Duty Roulette will be enough to keep the party queues popping fast enough for that?