FitzTheRuke
Legend
I think we can conclude that the initial print runs, which they said were so large that they couldn't print all 3 books at once (which lead to MM24 coming out in 2025), consisted of more copies than existed of the same 2014 books until 2016.Somewhere someone at WotC posted it sold more in its first months than the first year of 2014, or something like that.
And I can attest that they did NOT meet initial demand. I would not be surprised to learn that they sent an order to reprint the PHB24 before the MM had finished printing, and it had to wait!
Further, they may have even shortened the MM's run to cram in a run of PHBs, which would explain why there was only a brief window where supplies of PHBs were low, but a slightly longer (and more surprising) window where MM were hard to source.
I am basing this on personal experience, what I read, what I saw. It's possible that there were regional shortages or shipping issues that explain things differently. But I think that this picture can't be far from correct.