I figure that if I put a stick in my ear, I might cause hearing damage because of irritation, displacing wax, causing tinnitus, etc. If I put a swab in my eye, it might cause irritation and blurry vision.
By connecting the dots, if I stick a swab at the bottom of my nose, I suspect, that it could really impair my sense of smell. Especially if it was already damaged because of the virus and if the probing is repeated multiple times.
I am not surprised to hear stories of people not recovering from their loss of smell.
--> Because of that, I think they might be into something with the anal swabs, less danger of damaging a sensitive sensors.