May be you weren't aware of it but there have been MPs along Lawarence for many years. Some of them don't exist any more but I've personally known about MPs at 1315, 1719, 3482, 4117 and 4121 Lawrence for at least 5 years.
Since at least some of them have been around for more than 5 years, chances are they are going to continue to be in business for a while.
I've notice a major change though. There used to be only one MP at 1315 but now there are three. Either somebody in the compund will complain to LE and they will be shut down OR this location will become a MP district.
I hope it is the latter.
Also, it appears to me that city planners are licensing MP businesses along major areries e.g., St. Cair, Eglinton, Lawrence, Sheppard and Finch etc. Personally I think that is sensible.