Hey @Jensileus, thanks for posting.
The Router out of the box does not propagate response headers from downstream or subgraph services. We leave this up to the users to configure because we don’t know what to do if we were to have a conflicting header value. Keep in mind that your one query today might become a call to multiple services in the future with Federation and cause this conflict.
You can however set the Router response headers to the same value, you will just have to do so with customizations like Rhai scripts or Coprocessors.
See more details here: Header Propagation - Apollo GraphQL Docs