GraphQL form/variety trigger

I'm trying to get the 'why' for 'why' a Pokemon changed its variety or form such as with mega evolution I want to know which stone was used.
Is this already possible?

Here's my current query

query MyQuery { pokemon_v2_pokemon(where: {id: {_eq: 6}}) { id pokemon_v2_pokemonspecy { pokemon_v2_pokemons { pokemon_v2_pokemonforms { pokemon_v2_versiongroup { name } pokemon_v2_pokemonformnames(where: {language_id: {_eq: 9}}) { pokemon_v2_pokemonform { pokemon_v2_pokemonformgenerations { pokemon_v2_generation { name } } pokemon_v2_pokemon { pokemon_v2_pokemontypes { pokemon_v2_type { name id } } pokemon_v2_pokemonsprites(limit: 1, order_by: {}) { sprites } weight height base_experience id is_default } form_name form_order id is_battle_only is_default is_mega order pokemon_id pokemon_v2_pokemonformnames(where: {language_id: {_eq: 9}}) { pokemon_name name } } } } } } } }

Start with the provided GraphQL query and inspect the existing schema relationships for Pokémon forms, varieties, evolution triggers, and items. Determine whether the stone or other trigger is represented and queryable; done means the API can return the relevant trigger for a form change such as Mega Evolution.