"JB and others", yeah that's everywhere, so that part is true!

Of the FO's that left in May, 14 were probationary. That'd be 1.3% of the probationary FO's. Not sure I'd agree with the label "droves" for this.
Only one of those was hired in 2022, that could have been a training issue.
Majority of departures were Capt's moving on to greener pastures, simple career progression.

We'll see what June brings, that chart hasn't been published yet that I can see.