Does the BL65x or BL5430 support Matter?
Matter can be supported on the BL5340 (nRF52840) and the BL654 when using the Nordic nRF Connect SDK. However, due to the memory requirements of Matter it can not be used on the BL653, BL652 nor the BL651 given their flash and RAM memory footprint.The BL653 (nRF52833) has 512K of Flash and 128K of RAM and BL652 and BL651 has less than that.
There are instructions on how to reduce the memory footprint for Matter in the documentation on the nRF Connect SDK Main branch, Memory footprint optimization » Matter, but even using this you will not be able to get it down to a size fitting on the nRF52833. With the steps from the optimization page with the light bulb sample the size was reduced to approximately 730 kB of flash and 170 kB of RAM when building for nRF52840, which is still way too high for the nRF52833. Additionally, there are possibilities that the Matter flash usage will grow more before the official release, as more bug fixes and things from the Matter specification will be added.