Just an update: Focalcrest has updated the descriptions of the mixtile hub on their site and no longer claim to be HomeKit compliant, or even mention HomeKit at all. Now it just says “voice control,” which could be Alexa or Google home, both much easier integrations for a manufacturer than HomeKit.
My guess is that after CES 2017 Apple let them know that they have to go through separate HomeKit certification, just an mfI chip is not enough. And since there are specific functional requirements for hubs and bridges which this device as described did not meet, it may be a while before they get permission to use the trademarks. We’ll see.