Roof rack mounting bracket question

I recently removed my factory cross bars to replace it with a pro rack I got cheap. I followed the correct procedure for removing the bolts by taking them out together so the bracket wouldn’t fall out etc. When they were completely removed, I noticed the white plastic cylindrical bolt guides were either smushed down or cut flush with the roof. I really don’t want to go through the hassle of dropping the headliner and replacing all 4 brackets. My question is, are these plastic pieces necessary or are they simply bolt guides like I suspect? I’ve thought about trying to remove the rest of the white inserts and replacing them with something similar. Not my picture but resembles something close to this.
I’ll be using butyl tape and silicone on the bolts when I install the new rack.

 

Welcome. Whatever you do, just don't be shy with the amount of silicone applied.

 

if the thread is still visible i wouldnt worry about the plastic piece. and yes, dont be shy with the silicone. i ran into this when installing my rack last week...except i lost the thread piece and all. just put the bolt in and siliconed it all around. heavy rains the other day for over an hour and its all dry still whew haha.

 

FIFY.