i’d like to imagine, or hc, that in the case that harry removes tom’s soul from his scar, part of the abilities and rationality influenced from hosting the horcrux remains with him.
say, after 12-15 years of hosting the horcrux, depending on when they (tom and harry, or some other person powerful enough to remove the horcrux) finally remove the horcrux from harry, because harry has grown up with what little amount of tom’s soul in him, his thoughts, personality and abilities have integrated itself along with harry’s.
therefore, harry would subconsciously continue to have those traits because it makes up his personality, him as a person.
Though his abilities, i.e. parseltongue, wouldn’t come to him as easily as before, and he’d need to actually practice and study it a bit to retain and maintain the knowledge and understand the language and magic.
