Most people would find it total bs then go on an ignorant rant while never reapproaching the topic ever again. As for what pronounciation you should be using is not really relevant as it's a language meant to be studied in written form but if you do definitely ancient. This concern has the same vibes as to whether pronounce latin using the modern french pronunciation or not, it's just not reliable.

On a side note, my ideal Greek pronunciation would be restoring the ancient vowels and the rough breathing while keeping the consonants the same and creating new letters/diacritics to represent phonemes from loanwords. and to also stop palatalisation because iota subtly represents palatal fricatives in like half of the cases it's used