Hi Paul, please check the blog post https://www.evehome.com/en-us/blog/discover-your-thread-network on more technical details that apply as of today. By the end of the year Eve accessories that use Thread will start supporting Matter. Google said to go the same way, so it is just a matter of waiting here.
The current generation of Eve Motion is not ready for Thread. We will be releasing new hardware generations of many Eve devices with Thread support later this year, but unfortunately can't give any further details on when this will be the case for Eve Motion at this time.
Here's a list of all the currently available Thread-enabled Eve accessories:
Best regards, Volker
Jun 6, 2021