Yes, Los Angeles (at least) is in the process of limiting the amount of dispensaries to around 170 (latest number I saw), down from the supposed 600+ dispensaries currently operating.
They ideally want to split dispensaries by town and have a specific number for those towns. One I can't believe is Venice Beach. One of the bigger MMJ supporting areas, and there's roughly 13-16 dispensaries there, and the city wants to take it down to one or two.
However, it's doubtful that 400+ owners are just going to let the county shut them down and be fine with it. Expect this to be in courts for a while.