It seems to me that the question in the OP should have been asked of the CVS employees or manager while still in the store. Wouldn’t they be in the best position to answer this?
The labels are applied so ghat removing them would danage the packaging.
The whole point if the stickers is that IF you, as a would-be buyer, see the sticker on goods for sale elsewhere, they’re hoping you’ll be a good citizen & call the cops or the original legal retailer & tell them about the stolen goods being sold.
Never underestimate how dumb crooks can be; some will leave the stickers on.
The other point is the same as all forms of security directed against human attackers: Your security doesn’t have to be perfect. It only has to be better enough than the other target’s security so your attackers go there. If the stickers cause the bad guys to steal Walgreen’s products instead of CVS’s, then CVS has achieved their goal.
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One of the big changes in security with the advent of the internet is that now the enemy is a computer with nearly infinite resources, not a person. So security a bit better than the other targets’ gets you damn near nothing. Your security has to be 100% impervious against the threat to actually protect you from attack.
This difference is lost on a lot of people in positions of authority. Which leads to underinvestment in security measures & concommitant losses.
[/aside]