I'm just so curious and I haven't succefuly caught or want to catch an Unown on SS because they're all on diamond.
No. Unown can't breed because it's in the "No Egg" group.
The shape of the Unown depends on its IVs, so since hatched Pokemon's IVs are different than it's parents', the Unown hatched would be different even if the species could breed.
