Thresh not melee or ranged?

So i was messing around in a custom game and i noticed that thresh cannot buy runaans hurricane, reason being the item says Ranged Only. I also thought of how fun it would be if thresh could use ravenous hydra instead if he was changed to a "melee" champ, but found out shortly after buying it (it actually allowed me to buy it, unlike runaans), that the item is greyed out in your inventory slots and it says there, but not in shop Melee Only, and the items passive did not activate nor did its active.

My guess is that this happened with the recent runaans rework and maybe thresh was not on some list of "ranged champs" or something, i dont know how you all code that, either variable permissions for each champ or arrays of melee and ranged champs is my guess, but im just an amateur programmer. I just thought it was odd that he wasnt concidered ranged or melee.

(As a side note, just think of how fun, if not, funny looking thresh with ravenous/titanic hydra would be.)