I've changed a few tires on different wheels and added valve stems to wheels.
I notice there is a difference between wheels that are marked 'tubeless tire applicable' and those that are not.
The wheels that are marked Tubeless have very wide bead surfaces inside with a designated 'lip' on the inside edges of each bead shoulder that makes it a bit more difficult to 'seat' the beads initially when installing the new tire.
The Tubeless designation on the wheels has a safety feature in case the tire was to have a blow-out and instantly run flat while a person is riding it:the tire stays 'seated' when that happens. I haven't had that happen to me,and God help me if I did..
A tire could conceivably lose bead contact as I'm describing which would wrap the tire up around the rim in a strange way and expose the metal rim surface to the road;to me that's a 'worse case scenario',especially on a Front while I'm going around a corner.
I had a set of Suzuki mags which comes on the GS1100E that is meant to have tubes installed and these wheels have very small bead surfaces inside the rim with no inner 'lip' on the edge. I installed metal valve stems into them and mounted a pr. of Metzeler tires and they held-up well,the metal valve stem had a slow leak,which was a problem;I had never considered what would happen if I was to lose All the air in the tire at once.. although that rarely happens.