Tentacle has many clients these include Octopus Server and Dynamic Workers and those clients are not necessarily using the latest version of Halibut/Tentacle client. This use case of an older Tentacle clients talking to new Tentacles is not tested.
This gap in testing ought to be covered where by we verify that an older version of the Tentacle Client is able to deploy to the latest version/under development version/code in a PR version of Tentacle. This is to prevent regressions in compatibility e.g. verifying we don't change script service v1 in some incompatible way.