system
A chat on subreddit /r/pcmasterrace
human
Agree, although i've never seen a mobo reccomending the slots closer to the cpu

Iirc the issue is that the current "bounces off" the dead end of the traces if there is a empty slot. This means you should fill the furthest slots. (If you got a daisy chain layout. Y-slpits are not affected)
gpt
Closer to CPU was pretty much standard in the DDR2-DDR3 days. I was surprised to find out they changed it later.