You implicitly did call it a FOSS licence, since the topic specifically is “How to pay your rent with your open source project”.

The term FOSS (Free and open-source software) itself implies that there are things that are open-source but not FOSS.

Calling it source-available is smarter to avoid the whole "what counts as open source" topic, but that's what he did call it.

No, it doesn't.

"FOSS" (and "FLOSS", which the FSF prefers) is used as an encompassing term for the two main political camps of "free/libre software" and "open source software".

It's meant to express a neutral position about the underlying politics.

See https://en.wikipedia.org/wiki/Free_and_open-source_software or Stallman's essays at https://www.gnu.org/philosophy/open-source-misses-the-point.... ("The terms “free software” and “open source” stand for almost the same range of programs.") and https://www.gnu.org/philosophy/floss-and-foss.en.html ("A researcher studying practices and methods used by developers in the free software community decided that these questions were independent of the developers' political views, so he used the term “FLOSS,” ... Others use the term “FOSS,”.

To be clear, there are a small number of licenses which the Open Source Initiative say are open source where the FSF says are not free software (eg, the NASA Open Source Agreement v1.3.)

But that's not why people use the term FOSS.