Wrong, the whole point of end-to-end encryption is that security doesn't rely on intermediaries working as expected; they're only transports. Which is why having Telegram's server code wouldn't be useful from a security POV.

What it could be used for instead is running alternate "pods" to distribute load over multiple servers.

It's not all end to end. And there is a difference if the server is a malicious one.

Anyway, since the service is centralized and not federated even if it will become all end to end encrypted, it's enough of a reason not to use it.