No, AWS offers DocumentDB which is "MongoDB-compatible". In practice, it's incompatible enough that many people use MongoDB Atlas, which is the MongoDB-provided full managed database service for MongoDB.
Yes but I think that's why they changed their license wasn't it?
AWS had no MongoDB-as-a-Service before MongoDB Inc. changed their license.
Amazon can probably get volume discount, and sell with a nice margin to their gigantic customer base who will not care to reach for MongoDB cloud?