Over the last few weeks I have been contacted regarding this post and had contradicting reports that you are in fact able to create a feature to deploy content types to a content hub without the need for the feature to be enabled on each subscribing site collection.
My original issue experienced was also replicated by others once I’d posted this issue so this seems a strange one as since both of us are unable to recreate the issue.
Upon retesting the issue I can confirm that you are able to deploy a feature to a content type hub without the need to enable the feature on subscribing site collections.
Thanks to Chakkaradeep Chandran for following up on this and feeding back his findings.
*** Original Post ***
Raise it with Microsoft Create a PowerShell script that can receive a maintainable XML input file to update the content types on the hub. Not sure if this is possible but if the feature could be enabled on the subscribing site collection and have a dependency on the ‘Content Type Hub’ feature before deploying the content types.