Matter is not ZigBee. I believe it needs a whole new radio.
Thread uses the IEEE 802.15.4 PHY and MAC.
Zigbee also uses the IEEE 802.15.4 PHY and MAC, using the same frequency bands as Thread as far as I understand it.
Maybe a new radio is needed if you want BLE commissioning (is this required?), but for operation any chip with a IEEE 802.15.4 PHY should support both Thread and Zigbee.