Anyone know why ep 98 is only 4:3?
Because the TV version wasn't really 16:9. It was cropped and re-framed. The Blu-ray version is uncropped 4:3.
It was also announced that the DVD releases would contain the same (cropped and re-framed) 16:9 aspect ratio as the broadcast airing, yet the Blu-ray releases would contain a high-definition 4:3, full-frame aspect ratio. Both the DVD and Blu-ray releases would contain a Linear PCM 2.0 stereo audio track.