If you have a single Uno and remove it without closing the Serial Monitor and then re-insert it
At Ubuntu (Linux) Udev will make sure device has persistent name, above situation is working fine.
I don't think that will work if you plug 2 Unos into a PC at the same time
Udev rule is base on idVendor and idProduct, since both Unos has same id and this method will fail.
However there are few workarounds:
Plan A: One Uno and one Mega, different idProduct will make Udev rule work.
Plan B: One Uno and one Uno clone, different idVendor will make Udev rule work.
Plan C: Programming USB-Serial IC's EEPROM, make IC chip has new idProduct.