What do you mean by this? There is only one “database” in FoundationDB terms. You can write transactions over the entire keyspace regardless of which machine the data is stored on.
I'm still not sure what you mean in terms of contrasting this with DynamoDB's new features. You could implement the entire DynamoDB API, with even stronger semantics than the new features listed in the article, on top of FoundationDB. Additionally, the latency would be theoretically lower as they describe needing to do a read, write, and another read per key to verify isolation, whereas FoundationDB uses an optimistic concurrency control scheme to verify at commit time that transactions do not conflict. In the common case (where transactions don't conflict) this is faster.
All I’m trying to do here is trying to see whether the claim made in the blog post is true or not. Some commenters were claiming it was false, but I don’t think they considered all the components of the claim.
There's not really a concept of "Database" in FDB. There is however a concept of key spaces, and "directories", which are basically the same, and these all support transactions.