Aroa,
I am pleased to see that you have taken over the role of 'grammatical monitor'.
AOTW,
I tend to agree with you that 'anti-casaist' is a hyphenated word but I suspect it can be spelt both hyphenated and unhyphenated.
It is somewhat like 'non-compliance' which can be spelt a number of ways including one way, well known at an airfield South of Brisbane:
W-I-L-G-A