The author has a very literal notion of "shippable". Shippable could mean to a beta group. It could mean to the public. It could mean that the feature is "done" but not turned on or it's hidden behind a feature flag. Also, you are supposed to have retrospectives after each sprint to improve. This sounds like a discussion that should have happened with the OP's team at a retrospective.
Why bother redefining "shippable" just so that you can remain buzzword compliant?
Extract the good ideas, and leave dogmatic adherence to the charlatans selling buzzwords. If non-rigid use of a methodology leads to unintentionally missing out on a benefit of the methodology, whoever is selling the methodology failed to articulate that benefit.