It seems fitting, right? With their rough look and tribal lifestyle. But if you stop to think about it, there are some serious implications in an Orc becoming a werewolf.

It's about more than power, you become bound to Hircine in this life and beyond. Therefore your ties to Malacath, father to all Orcs are severed.

And don't tell me both allegiances can coexist. I hardly would think Malacath would take kindly to an Orc that serves/ is tied to another Daedric Prince.

It's the equivalent of a Nord forsaking Talos.

A very good point...

Yeah, i don't think that Malacath would take kindly to it ether.

I have an orc werewolf. I'd like to think he sees the shift in allegiance as an upgrade.

This. All this.
I role played an Orc once who was true to the Code of Malacath. She left the stronghold because she didn't want to be a 3rd wife to an unworthy chief and tried to make her own way in Skyrim. She joined the companions to fight for glory (and money, cause she needed it) but left them in a haste when learning of their secret. She spent the rest of her days searching for a good death, feeling shame that she had assisted and brought strength to Hircine's pawns, thusly betraying Malacath. So she thought anyway.

But wouldn't that make worship of all other gods from Orcs unlikely as well? From my understanding, worshipers of Azura go to Moonshadow, worshipers of Sheogorath go to the madhouse, etc etc? I've seen Orcs worship other gods, even Daedra in past games though.

You can roleplay an Orc that just doesn't care and that's alright.

Of course, if you planned to play a character that values their origins and tradition that ship's long sailed.