I think it’s slightly more nuanced - not all OTAs are recalls, and not all recalls are OTAs (for Tesla). Depending on the issue (for Teslas), the solution may be pushed via an OTA in which case they “issue a recall” with a software update. They’re actually going through this right now. For some other issues though, it’s a hardware problem that an OTA won’t fix so they issue a recall to repair the problem (ex: when the wiring harness for their cameras was fraying the cables).

This is 100% from the NHTSA shenanigans, though.