I thought you deserved a better answer to your question. Their are many snails that are referred to as "turbo" If you do a search of the internet, you will find that some of them do have a problem with righting themselves.
I got this from a website that sells something called a "turban" snail:
"Carefully place snails on a flat surface in your aquarium; if they land upside down, they may not be able to right themselves and will die."
Another sight sells something called a "star snail" and makes a point of explaining that the star snail can right itself, implying that it is their belief that some other types of snail cannot. From that sight:
"Star Snail A very interesting star shaped astrae that thrives in all reef situations. These do well in sand and can right themselves when turned up-side-down."
Another sight has the following warning:
"These inverts are great for an aquarium of any size. Because they are part of the "clean-up crew", they will go over every inch of your aquarium! While they are fun to watch, be sure to watch them closely. If they were to fall off the glass, rocks, or are bumped during cleaning and are found upside down, be sure to right them immediately. They cannot "right" themselves and they will die of a slow death - over a few hours."
Another question and answer sight had the following exchange:
"Hello. I have a quick question. I have some turbo snails along with a Chocolate-chip starfish. It seems like every so often, some of the snails along with the starfish (not at the same time) fall on their back. It seems to me if I didn't assist them in getting right side up they never would. Am I wrong? Is it possible for them to turn right side up?
<No, they don’t have any method/mechanism to self-right. The starfish has a better chance than the snails however. If either have substrate within short reach they often rectify however this is the main cause of loss of snails in aquaria> "
An "on-line magazine" sight discusses both turbo and Astrea snails, but only identifies the Astrea as a snail that may be unable to right itself. Under the astrea snail definition it says:
"Astraea Snails (Astraea tectum, Astraea phoebia) – Commonly spelled Astrea, these snails are handy at eating green and brown film algae that inevitably cloud our viewing panes. They are also helpful to add after a new marine aquarium has cycled and the Diatom bloom has started. Astraea snails are slow moving and slightly less desirable than others due to their inability to right themselves if they get turned upside down. Due to this prohibiting factor, when an Astaea is found upside down, the aquarist is forced to help them over which can be a tedious task. Although they are useful for film algae, due to their inability to right themselves it is recommended to only put 1 per 5 gallons of water."
Another sight says that Astraea snails are commonly called turbo and:
"Asterea snails (Astraea tectum), also called Astrea, are particularly useful herbivores for clearing algae (both green and brown) from the walls of the tank. They will also clean the substrate and live rock and will not grow in excess of about one inch. Despite their excellent algae-eating ability, slow-moving Asterea snails have one major downside—they are unable to right themselves if they flip over. For this reason, it is generally recommended to add only a few Asterea snails—perhaps one snail for every six or seven gallons of water."
I found similar warnings regarding margarita snails.
In short, it depends on what specific kind of snail you have. The answer is "maybe".