People who play Destiny 2 on Stadia will be able to play only with other Stadia players, an FAQ on Bungie’s website has revealed. Stadia players will not be able to play with PC players, as some had hoped. The lack of cross-play is not unique to Stadia. Destiny 2 multiplayer is bound to each system.
However, Destiny 2 will be going free-to-play in September and will feature a Cross Save function, meaning players will be able to play their character between systems.