As far as I know, MCAS has never activated in service due to actual high AoA. However, even the 737 classic could have "interesting" pitch up characteristics:

As far as I know, MCAS has never activated in service due to actual high AoA. However, even the 737 classic could have "interesting" pitch up characteristics: "The Boeing 737-300 was on approach to Bournemouth Airport following a routine passenger flight from Faro, Portugal. Early in the ILS approach the auto-throttle disengaged with the thrust levers in the idle thrust position. The disengagement was neither commanded nor recognised by the crew and the thrust levers remained at idle throughout the approach. Because the aircraft was fully configured for landing, the air speed decayed rapidly to a value below that appropriate for the approach. The commander took control and initiated a go-around. During the go-around the aircraft pitched up excessively; flight crew attempts to reduce the aircraft’s pitch were largely ineffective. The aircraft reached a maximum pitch of 44º nose-up and the indicated airspeed reduced to 82 kt. The flight crew, however, were able to recover control of the aircraft and complete a subsequent approach and landing at Bournemouth without further incident." https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-thof-23-september-2007 https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-... If that had happened in a Max, without MCAS, would it have ended badly? We'll never know, but it seems possible.