Sure why not? GraphQL is not specific to social products.

Any application where a user might want/need bits and pieces of various objects pieced together would be appropriate and that's a lot of applications.

For example if you are loading a user's dashboard view you may need basic user info, their unread messages, the list of objects they are looking at (e.g. list of invoices) and things like that.

Without GraphQL you'd be making separate requests to pull all of that together, with GraphQL it can happen in one round-trip.