Do you think his public rankings are purely BPA or maybe some tweaking to stimulate views and talking points?
Button is not one of the draft analysts who use what I call "shock ratings" to boost his visibility. Button already has the visibility. But he
is one of the analysts who falls in love with a player or is critical of a player in his early viewings and then tries over and over to justify his early ranking instead of adapting.
If you look back at Button rankings over the years, some of his more unconventional rankings look alright, but others look downright awful.
2015: Button ranks Oliver Kylington #8, Nick Merkley #10, Jansen Harkins #14. Mathew Barzal #19!
2016: Button ranks Brett Howden #18, Cam Dineen #22, Vitali Abramov #23.
2017: Button ranks Martin Necas #7, Timothy Liljegren #10, P-O Joseph #13, Alexei Lipanov #22.
2018: Button ranks Serron Noel #14, Bode Wilde #16, Filip Hallander #21, Jacob Olofsson #25.
From those series of anachronistic draft rankings over 4 years, we can determine that Button is --- well, very unpredictable. He has a few old-school Canadian Fs (Merkley, Harkins, Howden, Noel) and a few fast Swedes with size but hockey IQ questions (Kylington, Liljegren, Olofsson) and occasionally becomes enamored with a Euro forward with high upside but significant risk (Abramov, Lipanov, Hallander). Sometimes he nails it by bucking convention -- I remember also ranking Necas in my top 7 when his consensus ranking was around the early teens. Other rankings of his just look awful in time -- up-ranking Kylington 20 spots while down-ranking Barzal a dozen in 2015 did not age well.
However, in 2015 Button created actual controversy by ranking Noah Hanifin -- the consensus #3 overall pick -- in the late teens. This not only bucked Button's own convention of generally liking big, fast defensemen, but it also was a unique and -- as it happened -- very accurate ranking.
So, I always pay close attention to the Button rankings. I feel he is the closest approximation to the variance from NHL scouting team to NHL scouting team. This is to say that there could be a team or two out there which have Zachary L'Heureux in their top 10, but there's also probably more than a few who have left L’Heureux out of their first round altogether.