you're still correct.

"open source" is ambiguous (in cases this is deliberate)

OSI has its own definition of open source, but there's no reason someone can't say their code is "open source" because you can see the source code.

This is akin to saying 10tb hard disk... very few people quantify this with tera or tebi or Ti or whatever unless there is some legal fineprint required. and there is no hard legal definition for calling something "open source".

In any case, stallman has a take on the difference in philosophy of the OSI version:

https://www.gnu.org/philosophy/open-source-misses-the-point....