Since 343 relies a bit on lore, I don't think that's likely. The armor he's wearing means he's a Kaidon, a ruler. He now rules the state of Vadam. Not just a state, but a whole faction as well, the Swords of Sanghelios. Yes, he still holds the title of Arbiter, but, at least as noted by Halopedia (and I'll quote):
Quote:During his visit to Mdama, he announced that he no longer felt he was an Arbiter, but simply a kaidon.Despite this, Thel 'Vadam continues to hold the title of Arbiter as of October 2558.
As for the rest of the Sangheili, I believe so. Not only are the Sangheili models of H2A and HW2 highly praised, but 343 also put up a statue of an H2A styled Ultra Elite in Outpost Discovery. In general, 343 has been using those models much more frequently.