I don't know why but for me Tyranitar comes slighlty better in both DPS and TDO than Rhyperior when I use the spreadsheet.
Of course there will be other dark Pokemon surpassing Tyranitar in DPS, crunch is absolutely terrible. But the difference in bulk is huge.
Worst case scenario Tyranitar becomes a good Rock attacker and a decent tanky Dark attacker. Best case scenario one of the upcoming changes makes TDO more important than DPS and Tyranitar remains a top attacker for both types