The decoupling idea did occur to me, but I did kind of slide over your wording concerning the coax shield.
A few more clue requests:
By "connected," do you really mean connected galvanically to the shield? Or just folded around the coax tightly? Can't tell by the photo for sure. One picture I found looks as if there might be a sliver of shield exposed on the end of the mesh closest to the antenna. If connected, please describe how that's done (one or two places; by solder?).
Does the adhesive cover the central area of the mesh at all?
My thought was attaching the mesh to the coax was simply for product packaging purposes and was intended to be only temporary until applied to the antenna.
Maybe the mesh does both functions. I don't think the entire mesh area is needed for decoupling.
Interesting. I was also wondering about it being some attempt at common mode decoupling, like a 1/4 wave stub.