They’ve spent the last 15+ years dumping on millennials for being entitled or special or for ruining everything. “They’ve ruined the housing market”, “they’ve ruined shopping”, “they’ve ruined guacamole!”
And now millennials (and gen z) are over it. So they just say “Ok Boomer” and it triggers them like none other.
So no, Ok Boomer is not done. It’s just getting started. Your opinion matters less and less by the year so get used to hearing it as your generation fades.