Can one find out for a given block which bakers were deactivated through an RPC call? Is there any other way to explicitly find baker deactivations?
I don't think it is possible to directly find deactivations, however, one can use the
../<block_id>/context/delegates?active RPC for successive blocks, compare the results, and infer which bakers are not active anymore. Then one needs to check the balances of those bakers to see if the reason for deactivation was lack of funds or inactivity.