There was two changes, the split MAF table went to 12,200Hz and is limited to 511.9922g/s, in 2008 it changed to a 15,000Hz upper frequency limit and massive g/s limit. Main reason is they went from standard scaling to floating point numbers in 2008, that is a pretty major code change.
So on the older ECM's, even though it might be possible to extend the MAF frequency above 12,200Hz you are still going to be limited by the mathematical limit of the scaling used to get the highest g/s value (511.9922g/s). So there is not a lot of point to extend the frequency range.
Cheers,
Ross