All the 757s seem to be going down to 221/223 seats, to give 3 rows of 34" pitch in the forward cabin.
The main marketing reason for this is that the existing legroom seats are all at exit rows, and so there are strict limits in who these can be sold to, and also limited in number.
The comment for next summer seems to indicate the 737-800s will also get a dedicated extra legroom rows within the cabin, distinct from the exit row areas.
The 5% would indicate the only aircraft not featuring this are the 767s used on a limited number of short-haul flights. These obviously have extra legroom at exits - but not the unrestricted extra legroom rows on the reconfigured 757/737 fleets.