The old meaning is Greek, and to say that someone should be anathema due to their teaching, is to say that they should be rejected as a teacher. Yes, rejected strenuously.
If a stretched inference of “anathema” is what you are hanging your hat on, I think I’m done here.
It was condemnation.
Don’t let the door hit you.
anathema: that which is laid up, i.e. a votive offering Part of Speech: Noun, Neuter
Transliteration: anathema
Phonetic Spelling: (an-ath'-em-ah)
Short Definition: a curse, a cursed thing
Definition: a votive offering, a thing devoted to God; a curse, the thing cursed.
HELPS Word-studies
331 anáthema (from 303 /aná, "up" concluding a process, which intensifies 5087 /títhēmi, "to place") – properly, place up, referring to something pledged (given up) to destruction; a divine curse/ban ("accursed"); an "oath-curse."
b. a man accursed, devoted to the direst woes; to execrate one, 1 Corinthians 12:3
Romans 9:3 (pregnantly equivalent to doomed and so separated from Christ).
http://biblehub.com/greek/331.htm