Sorry I thought people were saying that Cineworld is telling them to pick up their tickets 20min prior or they will be cancelled. When in fact the website says they will be cancelled 10min after the show start time (which they aren't enforcing as you say).
No the website says that -
- they "may" be cancelled if you don't pick them up 20 minutes prior to the performance
- and "will" be cancelled if you don't pick them up 10 minutes after the start time.
The two statements are not mutually exclusive, and work quite logically together.