Have you heard any more? The previous head at my school went, along with the whole governing body, but that was a combination of factors and was done with enough notice to get a new head, not a march-off-the-premises job.
Our head was forced to leave about a year ago- same as you- no notice. he didn't even get to say goodbye, here one day , gone the next. we had a super head drafted in for a year- which was stressful - and now have a new head and things are calmer.
I think our head went because he hadn't met targets and wasn't being seen as taken on county advice. we had had a satisfactory Ofsted and a dip in KS2 results. But , to be honest, we never really knew, it was just rumours.
Hope things sort them selve out soon, it is an uncertain time.