yep, no go. But I do believe that you can insert a screwdriver behind the grommet and pull it towards the center of the car, it will pop off, but only after a lot of force, then you'll probably have to pull out the tabs again that's on the grommet so that there's still some tension.
I couldn't work around it, I did have to cut the latch from the grommet, but then re-engineered it with some other tools/parts so that it still serves its purpose.
Oh, and the pillar is dead quiet now
I may actually eventually order the grommet, but truth be told, it'll work just fine with how I redid it (read: zip ties!)