I see this type of rack in almost every trailhead parking lot. I haven't heard of many problems with the weight pressing on the rear glass but I should report that my brother broke the rear window on his 2012 Hyundai Santa Fe using a rack like this. We had both our 40# conventional Trek MTB's loaded on an older Thule rack rated for 3 bikes at 35# each. The bikes were in the positions closest to the vehicle. We were driving on a fairly rough dirt road when the rear window shattered.
Admittedly, this is a rare incident which could have been caused by the window design or a defect in the glass itself. None the less, neither of us will ever use this type of rack again, especially with our somewhat heavier e-bikes.
Again, this is likely a rare incident so take this post FWIW.