The article mentioned we have already received 6.1M Moderna doses - that's a ceiling for the maximum possible number of first doses. 7M is sufficient to cover everyone.
The devil is in the details. There is no additional supply until what they have is used up.
The problem here is the City of Toronto only books appointments for the supply that they have and expect to have. They are not going to overbook appointments in the hopes that the province gives them more doses.
Some of the GTA locations mentioned don't have a surplus, however, and are already waitlisting. It also doesn't include AstraZeneca second doses. So it will be good for some of the areas included but not for all.