Yes - pretty much the same protocol as all the other A380 operators which have Y at the back of the upper deck - boarding through UL1 and through half the J cabin.

I don't think really a big (or even small) deal though - as you say, it's the same as the 777. Perhaps it will be make passengers listen to lounge announcements as to when to board instead of being paranoid and getting to the gate early "just in case" to wait around and board at the same time as the Y pax, if they really, really feel uncomfortable about the fact they may be seen sitting in the J cabin as Y pax walk past, but then, I don't see anything wrong with that and am at a bit of a loss as to why anyone would feel too uncomfortable about that...