Quoting Addicted2DVD:

Quote:
No... I seen many first run airing in widescreen (when they originally aired on TV). It switched over to widescreen (original airing) sometime about half way through the series.

Maybe with later seasons of Friends, but I think most, if not all of Seinfeld was originally broadcast 4x3, as Seinfeld was always shot in 4-perf Academy 35mm negative (4x3).

Friends, was shot in 3-perf Super 35mm. With Super 35 (a production only format) any aspect ratio can be achieved. The problem in remastering shows from that era is, often the camera operators shoot off sets or show details that shouldn't be in the frame, since they were optimizing the frame for regular 1.33 TV (4x3). When that happens, they usually blow up the image to fix that one shot, and then go back to normal once the camera operator frames the shot correctly.  For a lot of these shows, there's a lot of extra area on the left and right, since the framing was always intended to keep all the important information in the center 4x3 area.

Super 35 3-perf shows won't be nearly as much of a visual compromise when and if they get remastered for 16x9. But everything made prior to the mid 1990s will have to be reframed, unless they opt to just pillarbox it and have the 4x3 in the center. Some studios resist this for television shows, and are demanding some kind of tilt & scan in order to blow up 4x3 shows for 16x9.

Edit :

Here's a found image that illustrates the point: the original 4x3 image as framed by the DP and originally broadcast, and the reformatted for HD 16x9 image....a bit more on the sides, a lot less top/bottom. The composition/framing is no longer the DoPs but that of some lab tech.