the led backlight of new displays is more efficiently directed through the lcd and onto the screen, so that the few light left leaking through the backside is not enough to brighten up the logo uniformly and with enough intensity.The glowing Apple is iconic... What would be a valid reason to end it?
no, i have no clue, but with this one you'll have an interesting story to tell your friends in case they come up with the question.
p.s. tbh the reason could be about that.