I don't know that I call the 767 Envoy seat reduction a bad thing when the seats themselves improved (even if they are a little crammed into the cabin).

I don't have the dates, but talking about the overall airline service quality downgrades:

elimination of closets on most domestic Airbus
reduction of A321 seats from 26 to 16
reduction of A330 Envoy seats from 42 to 30 to make way for more coach rows with a reduction of pitch from 33-34" to 31-32"