> but the entire product must still undergo the relevant testing for 2.4GHz emitters.

To be fair, it's unintentional radiator testing that's required, rather than everything the module had to go through as an intentional radiator. So, it is a "free pass" for nearly all of it, and a much cheaper one, since you don't have to use a costly FCC accredited lab.

Modular Approval is an FCC thing only. CE doesn't have it.