But this is true for lots of solids, not just glass. Consider creep deformation [0] which is deformation mediated by diffusion of defects in solid materials. It’s a big problem in metal turbine blades, it limits the maximum usable temperature to well below the melting point.

The physical mechanism would be similar in glass flowing in this way, so I don’t think evidence of glass flowing like this should make us think of it as a liquid instead of an amorphous solid

0: https://en.wikipedia.org/wiki/Creep_(deformation)