When you're talking about Linux, it's okay to say that it's "open source".
It's okay to say that it's "free software".
It's okay to call it "GNU/Linux", "Linux", or to mess up its name.
It's okay to refer to it as "the one with the friendly penguin".
Part of RMS' legacy has been an incessant obsession with terminology and pedantry, overshadowing far more important shared objectives which are fundamentally emancipatory in nature.
Pedantry is not activism; it is alienating, not emancipatory.