> The "DeleteByQueryWork.java" class changed from accepting class to requiring IndexedTypeIdentifier now as first parameter.

Oh my, and this is API. I really thought this was SPI... Well, looks like I messed up.
Thanks for the heads-up, I'll update the migration guide and discuss the API break with the team.

> Do I use it wrong?

Well it depends.
If you are using the ORM integration you generally shouldn't need to use it unless you have very specific needs.
If you are not using the ORM integration, then it's your only way to delete a document, so you're using it right.