I do not know what country you are talking about. If this is China, then there are doubts about the reliability of these distributors. Perhaps it is the buyers who created the deficit artificially.
The FUD is a tool of politicians and engineered for believers, nothing else, and certainly has nothing to do with buyers/sellers or EE, at all in fact. Apples and oranges.
It is common practice to request both options at the distributor level, as both of those options are kindly & generously offered. I'm talking about genuine parts and the less-than-genuine affordable ones. Distributors are 100% transparent when asked nowadays and will provide prices for both options. Those distributors/vendors who are more involved will let you know what part of the logic and/or architecture is disabled or faulty shall your goal be to save cost on large qty manufacturing. (you get what you pay for).
From my experience in this region and in that part sourcing business, this doesn't affect the STM32 parts much, but more the common hobbyist & thinker chips rather (Arduino/Atmel/Microchip particularly). You need to be very lucky to find non-genuine ST parts... shall your goal be to save cost (good luck with that). Most if not all of those STM32 are meant to actually manufacture products that performs, and therefore the demand and market for non-genuine parts is practically none :/
I'm not familiar with LCSC nor had any dealings therefore I'll omit commenting. I might have a look one day. Heard JLC assemble boards with their parts, which is pretty cool service, I think...