I don't know if this has been brought up so far, I didn't find anything on the forums.
One issue I personally see with non-ladder players getting into ladder, is the wide map pool and player not being able to learn by replaying and learning the maps.
I know that a good map pool size is important, but as a newbie in 1v1, it is overwhelming to learn the maps decently enough to feel somewhat "I know at least what I am doing after a few games", especially on large 1on1 maps.
Thus, I wanted to suggest to only broaden the map pool depending on games played, ideally step-by-step.
Example:
- >10 Games the map pool is limited to 4 small maps of the current pool
>20 Games the map pool is widened to an extra 2 medium maps of the current pool
...
This would not be a "Preferences" pick, but just limiting the map chosen when new ladder players are present.
I am not sure how realistic this is in terms of workload for the devs but if doable, it would greatly help easing players into the 1on1 environment in my opinion.