Not sure about your conclusion.

In my manual it says ...

" 12. Install ornamental frame in rubber frame.
NOTE: Prior to mountin gcover, fill upper join of ornamental frames with MB window sealing compoung so that no water can flow under cover over back window"

"16. Make seal between glass and rubber fram as well as body and rubber frame with MB window sealing compound, Part number 001 989 31 20.
Note: Excess sealing compound can be removed with adhesive tape."

I assume they mean to say that there would be adhesive tape applied around the window opening ahead of installing window, but there is no mention of it.

Good Luck
Don