Don't get too used to that. Although I'm not a seasoned AZ flyer, I have yet to see an MD-80 with proper biz class.
The Alitalia MD-80s I've flown on were all-Y, but these was within Italia. They were also years beyond their time and threadbare, and more than a bit dingy. I love the DC-9 series aircraft (for the 2-3 seating) and wish more airlines would stick with these, maybe putting in new interiors. However, the AZ MD-80s were a bit uncomfortable... IIRC no pitch, no biz class...
I have flown on a brand new 319/320 (can't remember which) a couple of times. It was a beautiful plane inside, very new, very clean, cool interior. Cool looking green cloth seats (though I must say they were hard on the bum after an hour).
It had a 3-3 biz class but the B and E seats were very narrow making the ACDF seats wider than normal, and it had the adjustable armrests. If I was told I had to sit in one of those B/E seats, I'd refuse even if they did move the armrests, because the seat cushion could only be about 16" wide. This is probably the most harebrained scheme I've seen. I think BA has the same arrangement on some acft?
They've since dropped the 319/320 from the MAN-MXP routes and I've quit flying them anyway.