No doubt, but that doesn't mean they need to do many passes with said comb.
The older SRDs were deliberately constructed to only have nothing but Open Game Content in them, whereas the 5E SRD was apparently doing double-duty as not just an SRD, but also the "basic" version of 5E, and so had Product Identity as well.
The 3.0, 3.5, and d20 Modern SRDs don't do that; they're pre-constructed to just be rules and other mechanics that WotC was already fine with putting out there (although the d20 Modern SRD does have a few organizations and individual characters that it releases, apparently deliberately so).