I'll admit I didn't check all of them before putting them in categories. In retrospect I don't have a problem with the G2, but at the time I didn't include it because he only went for the note once. As for the "Like a Rolling Stone" note, it may be pitch-able, but is not at a solid enough pitch for me to bother counting. And as for the "Another Movie" one, I'll change that to a 5.
As for the thresholds, I will agree that in many cases it makes sense to start the high notes lower to include some late career highlights. On the other hand, David here already has more G4s than F♯4s, and adding extra small sections below those creates an odd aesthetic. At that point you're filling the section with early career notes which were not the point of the endeavor in the first place.
The guideline I try to follow is roughly "are there a fair number of songs where the singer tops/bottoms at this note", or, perhaps more frequently, "are there cases where the singer uses this note in a climactic way"? That's the logic I used when I owned the Sinatra thread and started his highs at D4, a decision that was controversial at the time but I think helped kickstart this updated attitude towards thresholds. With Gilmour, I could see his lows staying where they are, but his later solo stuff contains numerous instances of him using E4 and F4 in what I'd consider to be a significant/climactic way (and yes, I think we should take later-career singing into account to a reasonable extent, because impressive bits of singing in a singer's later years should be acknowledged a lot more than the old TRP2-era thresholds allowed for).
This is my personal attitude towards thresholds, and others can elaborate if they wish, but for me there is more to it than just making big threads for the sake of it.
Yeah, I don't really like following that guideline because almost every singer's voice gets lower with age and they find themselves having to treating slightly lower high notes climactically to adjust to their new tessitura. In a lot of cases those same "lower high notes" were notes that they were hitting by the dozen earlier in the career, so if we count them all as high notes, we end up with over-bloated threads where a single note spans up to an entire page scroll's worth of songs where the singer hits it. It's really excessive and unnecessary in my opinion, and we really have to find a point to draw the line somewhere. I mean hell, Zedd Squared pointed out to me how there's a couple instances where Jeff Scott Soto hits climactic-sounding notes in the B3 area, but there's no way that means we should expand his thresholds down to that just to acknowledge those.
Personally I think we should only be adjusting thresholds for aging/voice changes when it's a HUGE vocal change that makes it sound like the singer almost turned into a different person altogether. For instance, I don't think we would've considered F4s high notes for Warrel Dane back in his Sanctuary days, but the way his voice changed in the '90s definitely made mid fourth octave stuff much more significant for him.
I'm also just gonna say for the record that there's very few men that I would consider D4 worth counting as a high note for, even if they mostly top out in the mid/upper fourth octave.
I mean, I'd like to think the line has already been drawn by not just listing significant notes for every pitch. I'm also not a fan of the idea that just because it affects every singer means it's unnecessary and not worth implementing.
Additionally, I've found that despite this sort of compensation for older age, there's traditionally not as many notes from the earlier years of the singer's being added as one might think. To clarify: off the top of my head, only around 50% (maybe a bit less) of the notes between F4-G4 for Elton John are from before the mid-'90s, a small amount given that he has much more recorded music from that time period. Generally I find that this is because the singer uses those notes in less of a "significant" way when the notes are easier for them to hit -- that is, an F4 for Elton would more likely be used in a phrase/section that peaks/climaxes at something higher. So I don't think this sort of compensation contributes to as much unnecessary bloat as you might think, at least not enough to outweigh what I consider to be the benefits of accounting for the latter part of these singers' careers (or earlier if we're talking about low notes).
I'm typing this in a moving car atm so I hope this is making sense lol