Wait, this seems like some heavy bullshit. For AMC at least, you have to activate your rewards in 5$ increments in order for it to be available to use. Are you saying that now when you buy a ticket it will automatically use it whether you activated it or not?
Well I had like 85$ worth of active points because of what thediamondage said above - a couple weeks ago, an employee activated all my rewards without asking. If you have any active points at all, it forces you into using them now.
I took this pic a few days ago of the kiosk, you can see that it lets you delete/change the movie but you can't do the same with your Stubs points that get automatically applied. This is an older kiosk but it happens on the newer ones too so it's something they changed across all theaters.
What I've been doing is buying my tickets at the kiosk with MoviePass but without using my Stubs. Then after the movie I go to the customer service desk and hand them both my ticket stub and Subs card saying that "I forgot to use this, can you apply this to my account?" They've done it with no issues or questions.