never heard of such foolishness, even back in the day when radials were the 'new wave' nobody talked of "different alloys" for different tire types - considering Michelin has been making radial tires since 1948, maybe we should just use rims from old European trucks

I'd say someone at Old Cars Weekly should call this guy on his 'eggspurt' court cases, there seems to be
conflicting views .... and
these folks would have the definitive answer, or maybe the Stockton Wheel folks
the primary problem with radials on older rims is a dimensional issue, most use modern car tires designed for wider rims than pre-60s were, and some tire makers will specify rim dimensions acceptable for various tire sizes
Bill