I think it's worth clarifying a few apocryphal things going around here.
First of all, those notes are very much melodic. The definition of song is being thrown around very loosely here. If there was an instrumental behind those notes, you're telling me that you would count it as being melodic? This is akin to listening to a vocal track and then denouncing the notes because there is no instrumental behind it that none of them count. What kind of logic is it to say that the notes themselves aren't what are important, but whatever is behind them. Sure context is important. If a singer is trying to sing an A4 and has an awful voice crack and hits some random, cracked Eb6 poorly, it's safe to NOT count that as a reasonable note because it is not in any musical OR vocal context. It is an unintentional, broken note. If you were to put that on an instrumental track or not, that would not mend the note in anyway. But that brings me to my next point.
Second, since these notes ARE intentional (albeit squeaks) and following a very specific melody (the melody of the marker), I think it's safe to consider these notes in the first place. The next thing to look at it is the sanctity and quality of the note. Although these notes ARE intentional and of the intended pitch, they are very poorly done. Had this been uploaded by some random rangewanking user, we would mock him, call him shit, and to fuck off. Unsurprisingly, we DO have a way of scribing shit notes. We have red notes. And I believe this is a case where red notes are important. Because just hitting a note isn't the same thing as SINGING it. Listening to some of Grassi's other whistle notes shows how much the quality of those notes falter in comparison.
In my opinion, these notes definitely meet the requirement of being melodic, because believe it or not, singing a melody, even if it is synthetic and arbitrary, counts as singing a melody. However, due to the poor quality, the only way these notes can be considered countable is if they are CLEARLY noted as poor quality via red text. It's either that or they have to go.
This is probably the best summation of those notes that I've read.
About whistle-gate, I still think they should be removed. We don't allow interview/non-music notes in any other threads, so why should we make a special exception just for him?
I think you're putting too much emphasis on how important (or, in your eyes, unimportant) the whistle notes are. Holsety has already suggested that we spoiler the notes to merely acknowledge the notes, but we don't include them with the rest of the notes, which seems a fair compromise. The notes do exist, as evidenced by their spoiler-ing, but aren't exactly "in line" with the rest of the notes.
I wish I was who Björk was singing about in Vespertine.