If I am not to be mistaken, the reason why the museum is taking so long to be accessible is because (and please correct me if I heard this wrong) that there was a glitch that allowed you to take items from the museum.
To answer your second question, no. I believe the only way that people will have gotten museum highlights, would be because of the Season 2 Best Base Build Competition:
However, that ended in April, and we are already in October. I hope this answered your questions to some degree.