I read somwhere recently that DVB-S2/MPEG-4 receivers don't do 4:2:2, only 4:2:0 as with the 8PSK and extra video compression, everything's now just too tight bandwidth-wise and error correction-wise to accomodate the extra data.
I might be talking out of my rear, but I'm sure the theory went along those lines. I'm happy to stand corrected.
It may be true that only 4:2:0 is actually being used, but I'd have thought 4:2:2 would be included on the receivers, it would be silly not to!
Don't think it matters too much, as you wouldn't "really" notice the difference, resolution being mainly in the luminance Y component. That said, I'm not personally in a position to do a visual comparison!
(After MPEG4 compression. any supposed difference may actually be irrelevant!).