Yeah I just looked that video and it clearly shows that the IKEA Dirigera hub has three radio modules; one for Wi-Fi and the other two are both identical Silicon Labs EFR32MG21 series modules which in that configuration will obviously be used to have them as dedicated Zigbee Coordinator and Thread Border Router radios.
So guess that means IKEA choose not to take a risk on Silabs Multi-PAN multi-protocol technology either. That was the safe way as even if you save some money in hardware going with Multi-PAN multiprotocol on a single radio then would intead both need to spend more time on development and maintaining it plus risk having more dissatisfied customer if thier network get unstable or slow response if they add of devices.
Note that each EFR32MG21 MCU SoC does not cost much more than $4 US-dollar (or €4 Euro) even if you do not buy them in bulk, (and I can only imagine the price IKEA pays in their bulk orders), so it not that using dedicated radios in a smart home hub will make them that more expensive in pure bill of material cost, especially when you consider that using Multi-PAN multi-protocol adds a lot of complexity to the software stack which also cost money in development time for developers. Reference-> Access to this page has been denied.
By the way, I would alao like to give IKEA top-marks for inplementing proper EMF-shielding on all their components as well as at least trying to locate all radios as far away from each other as possible on that IKEA Dirigera hub, it really looks a great PCB design for a low-budget smart home hub. As long as their users do not put it too close to EMF/EMI/RMI sources (like other electronics or WiFi devices) then they will probably not have issues with interference.
PS: For both Zigbee and Thread be sure to read and try to follow all the best-practice tips here ->,Zigbee network optimization: a how-to guide for avoiding radio frequency interference + adding Zigbee Router devices (repeaters/extenders) to get a stable Zigbee network mesh with best possible range and coverage by fully utilizing Zigbee mesh networking