Since we are in the beginnings of Agent Vault (AV), I wouldn't be surprised if there were many similarities. That said, AV likely takes a different approach with how its core primitives behave (e.g. define specific services along with how their auth schemes work) and is specifically designed in an infra-forward way that also considers agents as first class citizens.
When designing AV, we think a lot about the workflows that you might encounter, for instance, if you're designing a custom sandboxed agent; maybe you have a trusted orchestrator that needs to update credentials in AV and authenticate with it using workload identity in order to mint a short-lived token to be passed into a sandbox for an agent - this is possible. I suspect that how we think about the logical design starting from an infra standpoint will over time create two different experiences for a proxy.
If I understand correctly regarding credential stripping then yes. The idea is that you set the credentials in Agent Vault and define which services should be allowed through it, including the authentication method (e.g. Bearer token) to be used together with which credential.
We don't have plans yet to integrate with Bitwarden at this time but this could be something worth looking into at some point. We definitely would like to give Agent Vault first-class support for Infisical as a storage for credentials (this way you'd get all the benefits of secrets rotation, dynamic secrets, point in time recovery, secret versioning, etc. that already come with it).
See my other comment regarding an example of this.