Umm, Boeing didn't provide pilots with any information on MCAS until after Lion Air crashed, pilots were not supposed to need to know about it.
I can see what Boeing were trying to do. From their point of view, the pilots are already trained (supposedly) to deal with the situation the MCAS may bring up, so why complicate things?
If the pilots had followed the prescribed procedure for inadvertent/inappropriate/runaway stabiliser trim (a procedure which has existed for decades, across all Boeing models) then these crashes would not have occurred and the pilots would be none the wiser about MCAS.