If what gives the posts authenticity is the fact that they come from someone's homeserver how can that assumption hold when posts are coming from the big indexer?
Discussion
are you sure indexers serve posts? I got the impression they only help you find homeservers faster, because looking them up on a DHT is slow
That is what you wrote. There was only one query to one server that returned all the posts.
Both. There is full content indexers and light-weight. But currently on beta what you see is full content: it serves content to you directly and then the client can verify with homeserver. On currently release beta prototype the client does not perform the verification with the homeserver, but this is comming (it's a must, obviously).