I don't really agree. There are always cases between cycles where something is more concretely addressed in the subsequent cycle. A salient example right now is taps for inverter connections in article 705, particularly for a load side tap. The 2011 NEC has some rules which can be interpreted this way or that, but which were simply not written to address that type of installation. The 2014 addresses feeder taps explicitly and the rules are much clearer. Between the 2014 and 2017 code, it is things like how to treat solar optimizer circuits.
If it's a case where it's truly a clear, substantive policy change in the code, then I'm inclined to agree with you. But when it's a confusion or argument over the meaning of language and a subsequent code clarifies, or it's something that addresses a technology that barely existed when the previous code was written, I think it's quite legit to follow the subsequent code. The way ramsy described it isn't wrong and shouldn't be unlawful in my opinion.