Knowing that you literally can't BO whore on mapgen does have the significant psychological advantage that you don't need to think about it.
It's not that BO whoring is necessary to get >1k+ but BO whoring is one of the most obvious thing to if you want to win more.
Other, often much more crucial improvements, like eco balance, unit movements, map awareness, are much harder to grasp and implement, while copying and practicing a BO for an hour is conceptually really trivial and will definitely result in you winning games.
So if you go in with a competitive mindset you either have to BO whore to some degree, or convince yourself before every game that intentionally ignoring the low hanging fruit is fine. The latter is annoying and the former takes a couple hours to do as there are like 10+ maps you would need to find and implement a BO for.
Even I, someone that definitely does enjoy the BO whoring aspect of the game, was put off by this.
I did look up BOs for one ladder month, played quite a few games that month, then the map pool changed, I would have 'needed' to do it again and so I was like "Nah too much effort" and then didn't play ladder again until literally this week.
In short: Map gen week is an amazing idea and should definitely be a regular thing! Maybe make it mapgen Sundays or something, so that we don't have to wait for an entire month between mapgen events.