That would be the logical conclusion, since it is the final RTS hero alongside the Goblin Alchemist whose abilities have never appeared in the class lineup.
That doesn't mean it would appear in the next expansion though. Blizzard could hold off new class inclusion for multiple expansions like they did with Shadowlands. Interestingly, the lack of a new class in Shadowlands sort of reinforces the idea that Blizzard's class goals was to bring the RTS heroes into WoW as classes.
- - - Updated - - -
I'm rather shocked that the DH is still only running 2 specs when Hearthstone has shown a rather realistic concept for a DH third spec that players would be very excited for;
https://hearthstone.fandom.com/wiki/Ace_Hunter_Kreen