Nothing to do with being legal or not and everything to do with such a thing sounding too much like "free advertising". The obvious argument against that being "free" is the hefty registration fees that ball and shoe and accessories companies pay be allowed in PBA competition.
Since they already pay to be registered (which has nothing to do with any kind of technical regulations), why not give them some talk on the show? "Oh, he's using ball X because it's got a pearl cover that helps push downlane more" or "Bob's using ball Y because it's asymmetric and can generate more backend on that pattern".
In the end, it's money. Plain and simple.
SH