Blizzard has no immediate plans for any more race/class combos except for Dracthyr.
This was from an interview released a month ago on June 7th.
Beyond that, the last few classes we haven’t really gone broad with, there are some thematic and narrative challenges with. There are some races, for example, it’s very hard to imagine being druids. I don’t know what a goblin druid or mechagnome druid would look like in Azeroth culturally, in terms of their traditional background and what the Druids of the Grove and Cenarion circle typically value and welcome in. I would never say never, but I don’t think we have any immediate plans for further expansion like we’ve seen over the course of Dragonflight, beyond drachtyr.