First, personally my philosophy is to have any smart home type stuff have a dumb backup. You never know what might happen to your smart hub or whatever so having physical switched lights/ appliances is important.
Second, hopefully this doesn't come across as patronizing but based on your post it sounds like you aren't sure about this. IP is not "The Internet". You can have your own little private IP network which runs without the internet. If this is an open standard there should at least be the option to create a local only hub which only requires your local network is online.
That's not guaranteed considering who is backing this project, but it should be possible.
Second, hopefully this doesn't come across as patronizing but based on your post it sounds like you aren't sure about this. IP is not "The Internet". You can have your own little private IP network which runs without the internet. If this is an open standard there should at least be the option to create a local only hub which only requires your local network is online.
That's not guaranteed considering who is backing this project, but it should be possible.