https://docs.mongodb.com/master/reference/read-concern-majority/#read-your-own-writes

https://docs.mongodb.com/master/reference/write-concern/#writeconcern._dq_majority_dq_

These two pages say that if you do a majority read after a majority write, you're guaranteed to read that write. If you are talking to the exact same node that is true, but drivers often don't talk to the same node. This is also an implementation detail and causal consistency is really what users should be using for this.