I propose 2 updates to the deprecated version constraint:

1. deprecated can be greater than schema version. I think it can be useful for case when schema author wants to notify client about future changes, e.g. to say in schema version 110 that since next major version 200 some field will be deprecated. One might argue that in such case author can publish schema 200 but say that it's not yet in use. However, I find such a workflow harder to maintain because author might not have schema 200 ready for release.
2. And an obvious one: deprecated should not be less than sinceVersion (or maybe even strictly greater).