i think you misunderstood him, it's not about the riders but the teams racing the bikes.
it is solely about being recognized as a non factory effort to gain the CRT advantages (more fuel and more engines), the rider does not matter when it comes to being judged if the team can be classified as a CRT.
there is nothing in the rule books on the technical side to determine what is a factory prototype and what is a CRT prototype, it has all to do with the money and the financing which determine whether you'll be judged as a factory and therefore denied the extra fuel and engines
if for example gresini could make a case that he bought bautistas rc213v and that he is funding that bike by himself without hondas help/without being dependant on honda even that could become a CRT bike
and hey, welcome to the board
edit : about the aprilia...as I understand it the difference between the aprilia and for example the honda is that aprilia sells the bikes to the teams so that the bikes become the teams property, honda on the other hand leases the bikes and at the end of the season the bikes need to be returned to honda. if there wasn't that much money and secret technology involved i guess if yamaha ,ducati and honda actually sold their bikes to the privateers that would be CRT too but that will never happen, its too risky to invest millions and millions into R&D and then have those secrets "stolen" for 20.000€ .