Some news for ya fwiw. First off AC and C is the common use name for Aspirin (not acetaminophen), codeine and caffeine. With tylenol instead of ASA the common use name is Tylenol 1 or T1 as Sorbate mentioned.
I met with someone in the industry (the college of pharmacists) today and while we were talking I remembered this thread so I asked him about the status of T1's as it pertains to this thread. His answer was that there is no expected change in the status quo in any of our provinces anytime soon. I asked about the situation in your home province specifically and he figured that this was possibly just a position being taken by the management of certain specific retailers which could be happening for many reasons, thinking of the similarities to the troubles with purchasing syringes in some places. Also there was a shortage of AC and C around the time you first posted but I'm not sure if that had any effect on the acetaminophen products.
Unfortunately I forgot about this last post of yours so I forgot to ask specifically about if AC and C has actually been discontinued but it doesn't make sense to me that it would if T1's were not.
Everything I said here is opinion based meaning I never fact checked but it would be a very big surprise to me that this man was wrong as he is in a position to know.
Cheers