I’d say "this could cause speciation. There is an astronomically slim chance of it occuring naturally if enough sinistral (lefty) snails meet and create a sustaining population (and also not die out through inbreeding). I don’t think there is a case of any chirally divided species. Maybe this once happened with Amphidromus inversus but presumably, the species have mutated since to be able to successfully mate both homo- and heterochirally. Now, a balanced population exists and hetero mating is more common.

However, as humans come into the picture and can find mirrored snails and purposefully put them together, and breed them in safety into a large population, speciation can indeed happen and the resulting mirrored snail can fulfil the same environmental niches as the original species while having an almost completely separate gene pool (only the mirror mutants of each species can cross-breed - and if my above theory is correct, the advantages of tapping into a new gene pool may have then how dextral/sinistral then-subspecies of Amphidromus inversus eventually acquired unique breedability).