When you hear they have to get the numbers from Raleigh that is referencing DPI. Once Chapel Hill (NCHSAA) gets them they go through and combine or subtract out any students from the ADM. Example is five high schools are listed but in reality they are one high school (Olympic in Charlotte) or schools that have an educational program but the students are required to play sports at their home district school. It is a bit more complicated than what most folks think.
I posted about the same thing on another site and if I had paid more attention to an article I read I won't have made the mistake of stating the schools turning in thier ADM to the NCHSAA. Someone pointed out that the school reports it to the DPI and the NCHSAA pulls I'll say the original ADM numbers off that. But yes according to a highschool OT article explaining the playoff system it doesn't stop there.
"The NCHSAA will receive average daily membership numbers (ADMs) from the North Carolina Department of Public Instruction. Once these numbers are received, the NCHSAA will make some adjustments to account for early colleges, academies and other special circumstances, then the numbers will be released to the public on the NCHSAA website. Sometimes there are small corrections that must be made after the numbers are released. This typically happens in the last couple weeks of the regular season."
Of course this makes me think were people are talking about the early ADM numbers these are the numbers the schools have turned into the DPI and wouldn't include any Early College students which depending on the EC could be added to the NCHSAA final ADM.