AMS entirely depends on where you are coming in from - this is due to how the transfer system works there with passengers freely mixing airside. Trusted countries Schengen/UK/US/Australia etc do not need baggage scanning on arrival but come in from places where the Dutch do not trust the security and they want your bags scanning. Years ago things were different and there was a non-Schengen>Schengen bag scan but it was changed in 2015.