MongoDB 4.2 using change streams with read concern majority disabled in a PSA deployment
This is not the expected behavior. Since you have the majority members of the replica set online, it should work 

Just wanted to confirm:


Are you using version 4.2?
After installing/upgrading the replica set, have you set the feature compatibility version to 4.2 by executing the below command?

db.adminCommand( { setFeatureCompatibilityVersion: 4.2 } )


Thank you!