Yeah all sorts of shennanigans can be, and are, played by the various university athletic departments. Some are legal, some are non-GAAP, some are truly shady, and some are probably illegal.
Ultimately though I agree with mb's point that these give us a directionally correct view of who is bringing in the most money, and I agree with CD's and FF's point that there are no surprises here and most of us could probably name most of the top 10 and in reasonably close order without actually seeing the data.
What's always of more interest to me, is how efficiently that revenue is converted into athletic success.