Technically true, but ONLY if those Zigbee devices have been added to SmartThings using matter over bridge. Like, for example, Philips Hué lightbulbs connected to a Hue bridge where the Hue bridge is then added to both SmartThings and Google home.
At the time of this posting there is no matter bridge available for the SmartThings platform that can take Zigbee devices directly connected to a SmartThings hub and bridge them out over matter.
And you can’t connect Zigbee devices of the type that work with SmartThings to both a SmartThings hub and another Zigbee bridge. You have to choose one or the other.
So if you want to use Zigbee devices with multiple Home Automation platforms, you have to connect them to a device which is a matter bridge. Then add the bridge to the multiple platforms.
This is how the Hue Bridge has always worked without matter. You could simultaneously connect the same Hue hub to SmartThings, Apple HomeKit, Alexa, Google home, etc.
And this is how the new matter bridges like the aqara M3 and the zemismart matter bridge work.
But you can’t connect a Zigbee home automation device directly to more than one hub at the same time. You have to go through a bridge and so far SmartThings hasn’t provided a Zigbee bridge out from its platform.
But if you start by connecting the Zigbee device to a matter bridge, like, say, and INNR lightbulb connected to a Hue bridge, you could then connect that Hue bridge via matter to both SmartThings and Google home and the lightbulb would then show up in both. So you’re using a matter bridge, but it’s not provided by SmartThings and you had to use that bridge to bring the device into SmartThings. Not connected directly to SmartThings hub.
