THCa / CBD bud sprayed with isolate

A buddy is raving about THCa they have recently found a source for. The flower looks great and effects are there.

Some websites that offer THCa flower state that it is CBD flower sprayed with a hemp derived THCa isolate, some others dont offer this information on their product.

The THCa extracts sometimes list their ingridients as hemp derived THCa, hemp derived CRD and cannabis derived terpenes.

Does anyone actually know, are all sources that offer THCa flower/extract selling CBD flower/extract with added isolate? Or are some selling straight THCa products?

Looking for definitive answers ideally and not speculation.