Bumpers shouldn't be absolutely necessary even for people who can experience signal loss by touching the left spot, as I can do with mine (depending on where I am). It took me all of 30 seconds to find a new grip that avoids touching that spot, and I probably never would have thought about it again if not for the internet nearly imploding over the issue.
You can argue over whether it should be necessary to hold the phone even slightly different than one is used to in order to be sure it works, but in reality it takes such little effort to avoid the issue that I'm pretty sure any adult with standard functioning hands should be able to do so until their bumper arrives.
You can argue over whether it should be necessary to hold the phone even slightly different than one is used to in order to be sure it works, but in reality it takes such little effort to avoid the issue that I'm pretty sure any adult with standard functioning hands should be able to do so until their bumper arrives.