It should work with any Shimano 2:1 shifter. Revoshifters came in 8s. The drop bar brake/shifter is new for 8s.
The one way clutch device makes it hard for slack to form in the chain over bumps. This coupled with a Narrow/Wide chain ring (1x only) keeps the chain from coming off. Most of these offroad derailleurs have a lever to release the clutch for changing wheels. I don't think this one has that. Maybe someone in UK can tell more about this. I can't get one here yet. The whole clutch derailleur thing started with 10s and up. I just leave mine switched off (Zee M640) for smoother shifting. But could switch it on for any rougher situations.
But you can adapt any 10,11s derailleur you like to 8,9s by running a SRAM 1:1 shifter. The cable pull is compatible between Shimano and SRAM in 10,11s. You can also adapt 8,9s bikes to 10, 11s using newer parts. 10s cassette is narrow and needs a spacer, 11s MTN fits classic HG hubs, Road 11s fits GH11 which is also vintage Mavic. 12s they went to proprietary splines to get 10t top gear. Why bother?
The wide 8s 11-45t cassette is new, and the integrated 8s shifter/ brake for drop bars is new.
The derailleur has more capacity than legacy parts but is compatible with those shifters. The GS cage has more ground clearance than SGS on 26" bikes. But there are many other options for derailleurs. As a groupset it's for lower end "Active" bicycles. Entry level parts. Much better than the Acera derailleur they listed with the 11-40t casette. My Ebike folded that one up in 100 yards.
If you don't want the wide range The Zee M640 has an SS cage, and can go up to 11-42t.. 2 versions DH for 11-28t, and FR for 11-36t. But those ratings are for suspension bikes. On HT bikes it can go higher. 11-40t is within the listed SS cage capacity of 29t. It's pretty nice in 11s.