Maybe #5024-5025 are #5075-5077 replacements and #5078-5099 are not being sent to MJQA. I don't think because one buses goes the whole set is being swapped out I'm just saying.
I remember those day #9280-9344 Were fresh never popped up on the B6 until the 2000's. They were Rockets all of the 92xx & Most 93xx went to queens Ain't that krazy. They were murder rush on on the B1, B6, B36 & B74 i rather then on the Low used routes.