This page[1] has a pretty good explanation. "Simplified process" probably wasn't the correct term to use. I think in a new product that integrates an RF module

This page[1] has a pretty good explanation. "Simplified process" probably wasn't the correct term to use. I think in a new product that integrates an RF module, you still have to at least do testing for unintentional emissions. And if you do something like change the antenna, in my understanding it's possible to update the FCCID instead of recertifying and getting a new FCCID but you'd need support from the original vendor which is probably unlikely. It is obvious that lots of small companies do not do any testing/certification and a lot of webshops practically encourage you to mix and match radios and antennas so I don't think this is well-enforced anywhere. One funny thing is you're actually not supposed to change antenna types as an end user either. Radio module manufacturers are supposed to use proprietary connectors or integrated antennas to avoid this so the end user can't just buy a high gain antenna and connect it. Unfortunately (or fortunately) this usually means they use reverse polarity SMA connectors instead of SMA connectors. RPSMA connectors became so popular that today it's easier to buy an RPSMA antenna than an SMA antenna.