I am pretty convinced this theory is true. For me, the strongest evidence is in the post-show credits. Both Wilson Cruz (Doctor Culver) and Kenneth Mitchell (Kol) get their own intertitle as full-on guest stars. Culver has a 30-second conversation with Stamets and shakes his head over Landry’s body while Kol is clearly a secondary player to Voq in the Klingon storyline. Meanwhile, "Javid Iqbal" gets this:

He has to share the screen with a bunch of one liners on the bridge crew and the computer of a wrecked ship. Unless Iqbal has the worst agent in the industry, there is no logical reason why the Voq actor would get worse billing in the end credits than actors with much smaller roles. Unless of course he already appears in the main titles