If you search the forum and there are lots of threads about this, you will find that pretty much every maker and every player who has expressed an opion about guitars opening up agrees. If the guitar doesn't sound decent at the beginning, no amount of playing will make it a great guitar. There was one thread sometime in the last 18 months about a French guitar where the poster expressed some surprise that there was a dramatic change in the qualities of the guitar over a period of 6 months or year - sorry forgotten the details. That is about the only exception to the conventional wisdom that I remember being mentioned here.
Loads of posts about this over the years. Putting "ToneRite" in the search box brings back 206 posts. Lots of reading for anyone interested.