It is my understanding that the only de-waxed product from Zinsser's is the Seal Coat, which is a 2# cut, de-waxed product. I believe all the other to contain wax.
That said, even waxed shellac is apparently compatible with many finishes, and has been used by many over the years without difficulty. I think the problems arise with some of the new finishes, and particularly the waterbased finishes.
In fact, I often use the waxed shellac if I am out of the other, as a sealer under poly and other solvent based finishes, and I have never had an issue. Might 30 years from now, but honestly, those will be someone else's problem!!! Short of a miracle, I doubt I will be here.