

It doesn’t really matter whether Zigbee was merged into something else, because it simply doesn’t have any technical means of phoning home. It simply can’t access the Internet.
There’s no intermediate corporate owned servers, there’s no proprietary software.
So it doesn’t really matter what the corporation does because it can’t affect my “smart” devices.
Even if all support is dropped, everything is running on open source software, so nothing is going to stop working as a result of dropped support.
Finding replacements might become tricky at some point though.