The text you quote doesn't mean what you seem to think it means. He's talking about how much we can compress a stream, and indeed the amount of FLAC compression possible depends on the type of data in audio files. He's not saying that FLAC does some kind of violence to the data that WAV does not do. FLAC compression is still a completely lossless process, as one can easily verify oneself by repeatedly compressing and decompressing the same file and comparing the PCM data.
FLAC decompression takes place at the application level. The same data gets sent to the soundcard driver whether originating from a WAV, AIFF, or FLAC file. (Jitter is not an issue at this level as long as the application can supply the data fast enough.)
Now some people will blame the difference on the processor load, but decoding of 24/96 FLAC files takes up only a few percent of total CPU load at real-time audio processing rates. And processor load is constantly fluctuating from second to second and minute to minute, so one would expect audio performance to be pretty arbitrary if playback was this delicate.
FLAC decompression takes place at the application level. The same data gets sent to the soundcard driver whether originating from a WAV, AIFF, or FLAC file. (Jitter is not an issue at this level as long as the application can supply the data fast enough.)
Now some people will blame the difference on the processor load, but decoding of 24/96 FLAC files takes up only a few percent of total CPU load at real-time audio processing rates. And processor load is constantly fluctuating from second to second and minute to minute, so one would expect audio performance to be pretty arbitrary if playback was this delicate.