Maybe you can highlight/quote which rule they bent......I'm curious.
Don't have a current rulebook available but can't imagine it's changed too much in past couple of seasons. from Sec 7.7 Body:
Any new body designs, plans, pictures, specifications, or concepts
must be submitted to the NHRA Technical department on or prior to
Nov. 15 of the preceding year. All new body designs or concepts
must receive final approval from NHRA on or prior to Dec. 15 of the
preceding year or shall be deemed disapproved. Body
specifications may vary for certain exhibition vehicles; prior NHRA
approval necessary.
FWIW I understand the situation and logistics involved, particulalrly with the Camaro due for a redesign next model year. I see it at is somewhat unfair, but necessay for the overall good of the sport. As a fan I'll be temptetd to dog it a bit.

P.S. Not saying they didn't meet this requirement, but it would seem they could have come up with something besides a rework of the current body if they had the design complete by mid Nov.