We've discovered some concerns with xDS+RLS that we want to address before stabilizing. The current handling of cluster_specifier would NACK for unimplemented/unknown fields, but grpc/proposal#292 would make the behavior nicer to future additions. But that can all happen for the next release.

Closing for now. I'll reopen when the XdsClient changes are in.

#9014 had the necessary behavior changes for unknown cluster specifiers.

@apolcyn, how do we feel about this? The v1.46.x branch cut should have already happened at this point.

This should be fixed to our knowledge in v1.46.x, but it isn't entirely essential that it is stabilized in v1.46.x and the severity of the recent issues reduce our confidence such that we don't want to stabilize in v1.46.

@apolcyn, do you want to approve this now?