I would love to highlight SIA, Lo, VOW, HDLM and ÁvE
Edit: Personal point of view, gathering experiences from players from those teams, this doesn't mean they're better or worse than any other.
Starter pokemons which are given at the beginning of each storyline are shinylocked (they can't be shiny). However those can be found in the wild, aswell as breeding them to get a lucky shiny hatch.
Attached to xMago's reply, please add an english translation (even if it's from google) in your future posts.
Añadido a la respuesta de xMago, por favor añada una traducción al inglés (incluso si es de google) en sus próximos post.