Yes, they did, when MongoDB was licensed under AGPL. After MongoDB relicensed under SSPL, they release the API-compatible DocumentDB which is proprietary itself.
Sorry, I did some duck searching, maybe I am misremembering, but I can't find any evidence that AWS ever used MongoDB or offered it as a service directly?
Yes, they did, when MongoDB was licensed under AGPL. After MongoDB relicensed under SSPL, they release the API-compatible DocumentDB which is proprietary itself.