I can confirm that there is a difference in the frame masking with Photoshop CC 2014.1. Note the edges of this particular frame in one of my panos as stitched in Photoshop CC 2014.1 vs. 14.2.1:
However, is it worse? I noticed that Photoshop CC 2014 has seemed to improve the "big picture" blending between adjacent frames in Photomerge, Perhaps it's just because of the change in the mask positions, but to me the overall exposure differences between adjacent frames seem less visible when looking at the pano in overview...
Are you seeing that some panos appear more poorly stitched with the simpler masking?
-Noel