lern,
it became yeshivisah to say “oy” instead of “ay”
Can you please elaborate. As far as I understand, the older Litvak’s used to pronounce “Oy/Choylem” with an “Aye” sound, however, most of the Ashknazim pronounce it “Oy” Yekkes with an “Ow” , Sefardim with an O.
I don’t think it is limited to Chassidim at all.