[thfuran]

>Made has not the sound of bade

Doesn't it though?

[pja]

I think you might argue that the a in bade is stressed whereas the a in made is unstressed?

Otherwise I agree, there’s no difference between the two in my dialect.

Wiktionary suggests that it can be a homophone with bad in some dialects though, so perhaps that’s what the author was thinking of?