No, that's not changing the behavior of the existing tools everyone uses and aren't going to stop using. You can't say correct when you're not actually agreeing with his point.
It changes the behavior in the sense that there is no w=1 option. All whitespace is significant. The idea of ignoring whitespace would be like the idea of ignoring angle brackets in html. Whitespace is an essential part of TN and ETNs and is never ignored.
Diff tools then can benefit by showing not only aggregate line diffs but aggregate node and word level diffs without knowing anything about the meaning of a program.