Specifically in Pokemon sword and shield, there are some sites that list the raid dens that show if Pokemon with a hidden ability pop up and if they're even available to begin with. (Before Pokemon home transfer) So, catchable in the Galar region.
Trapinch seems to be available with it's hidden ability, but no dens have information of one spawning with it's hidden ability. Is it even possible too get?
Information seems to becomming more vague on most websites regarding the latest Pokemon game.
Alternatively, since Flygon does not have access to a hidden ability, do you think it's possible to just breed it?