I've never heard TOS or any episodic series described as an anthology, not in previous decades and not now. That term is used for Twilight Zone, The Outer Limits
, etc. Every episode is not just a separate story but has new characters and new actors.
At most, you could also call American Horror Story
an anthology series because each season is a separate story with different characters and premise. Anthologies are rare on TV. There's no point in saying "I want episodic Star Trek
" and then referring to it by the wrong name.