If you breed a Pokemon with an uncommon Tera Type, i.e. one you obtained from a Max Raid Battle, and breed it, does this have any effect on the Tera Types of the resulting offspring?
I bred a Flying Tera Type Pikachu with a Psychic Tera Type Ditto for 23 eggs, and the resulting Pichu all had an Electric Tera Type. No, Tera Types do not pass down through breeding.
Source: I bred them myself