In the same video, they also measure perf/watt under heavy load, and it's close to the M1, but not the latest gen M4. I think that's pretty good considering it's a first gen product.
Regarding the discontinuation, it's still on shelves right now, but I'm not sure if there will be future generations. It would be awfully silly of them to discontinue it as it's the best non-Apple laptop chip you can buy right now if you care about efficiency.