Why wrong? If you don't take the steps Linn do, it's perfectly reasonable for the different kinds of noise they measure to differentially and discriminably affect playback in the ways they describe it might. There's no law of the universe that says FLAC and WAV do sound the same kn all systems, just an expectation on my part that they ought to in a well engineered system. In contrast to Linn, Naim Audios own engineers say on the Naim forum that WAV on their systems sounds and measures better than FLAC, from which I conclude that Naim stuff isn't well engineered.
I am trying to say that the difference between processing flac and wav is irrelevant to the quality of the equipment. If the gear has the correct firmware/software in place and it has the capacity to run the software then all being equal you will get the same sound out. I'm not commenting on the quality of the resultant sound just that it will be the same.
My little mp3 player has the capacity to reproduce flac with a teeny battery that will play music all night (I have tried this). power requirements to decode flac is therefore bugger all.
I have a 24bit wav file and a 16 bit flac of the same music. I will do a comparison so at least I can say i have done my best for wav. (which is a pain to tag).