This situation is mentioned in the docs

https://tanstack.com/query/latest/docs/reference/QueryClient#queryclientgetqueriesdata

Caveats

Because the returned data in each tuple can be of varying structures (i.e. using a filter to return "active" queries can return different data types), the TData generic defaults to unknown. If you provide a more specific type to TData it is assumed that you are certain each tuple's data entry is all the same type.

This distinction is more a "convenience" for ts devs that know which structure will be returned.

So you could type the data by doing something like queryClient.getQueriesData<string>({ ...})

This situation is mentioned in the docs

https://tanstack.com/query/latest/docs/reference/QueryClient#queryclientgetqueriesdata

Caveats
Because the returned data in each tuple can be of varying structures (i.e. using a filter to return "active" queries can return different data types), the TData generic defaults to unknown. If you provide a more specific type to TData it is assumed that you are certain each tuple's data entry is all the same type.
This distinction is more a "convenience" for ts devs that know which structure will be returned.

So you could type the data by doing something like queryClient.getQueriesData<string>({ ...})

Yes, it is. But this mentioned is pretty old and being writed before we get queryOptions or inifiniteQueryOptions. It's strictly key may garanty for us, the touple will be exactly the same type, as returned from TaggetQueryKey type.

UPD.
If no one minds, then here is my proposal to fix the problems: #8614

getQueriesData is fuzzy, so even if you pass a key from queryOptions, there is no guarantee that the results will have only that type. You could have an entry with a different type that matches the key filter e.g. because it starts with the same key.

@TkDodo
Yes, that's right. Didn't think about it. At the same time, the getQueriesData method has an exact field. What if I extend the type so that if exact: true is present and queryOptions is passed, the correct type is returned? This would solve the problem, it seems to me.

UPD.
I sended another commit to PR for my idea reference