There are definitely RNG elements in the game. (as was established when one broke and was fixed in a patch before the next update... I think it was Talia after the Yacht content)... So Cell RNG is mostly if the girl ignores you/is busy/whatever other reason you don't get to interact with her that day. But as stated when you go to Killer Frosts after the story content stating she is going to be used by all your henchwomen (It's been a while since I did it last, that might even be the first cell conversation I don't remember) then there is RNG on whichever henchwomen who a, isn't currently assigned to you and b, doesn't already have a scene.
There is RNG similar to the cell lockout on Tala and Roulette, Roulette's you can get to happen less if you pay her.
As mentioned I believe Talia, Maxima and Ravager visiting after the Yacht are on RNG (though due to issues it may have been moved to a set number of days I'm not sure...) There are probably more this is just what I can remember off the top of my head but it is definitely an element present in the game!