It's already a pain in the ass to sneak away from the group to get a gun in the first place unless you spawn with one in your cell seeing as most rounds boil down to "9:50 Lava/Execution day, ok guys line up at 9:20 to play Simon says" and the entire round gets played in the same room so this would just make it even more annoying to play prisoner, so tbh

A lot of wardens dont do that, and either way there is a lot of ways to rebel with that kind of warden, you could just wait in your cell a bit longer and just jump into a vent a run. During freedays guards will most likely lose because they dont know who has guns so they just get killed by someone walking up to them and blasting them in the head. But during a day where there is a warden it will make very little difference as if you are rebelling you are KOS anyways.