The store won't really be all that useful to area residents, and I don't think it's locals that the store is targetted at in the first place. There's already a grocery glut in the area (I'm within easy walking distance of two Dominions, a Sobey's, Cumbrae's, Reither's, Pusateri's, the ever reliable Super Fresh Mart, a No Frills, and a Food Basics), and if they were catering to locals they wouldn't need two floors of parking.
I wouldn't say that.
The local Sobey's is an Express store, and is more akin to a convenience store than it is to a full-range supermarket. Cumbrae's is great, but it is a butcher shop, not a grocery store. Reither's, Pusateri's (not the version of Avenue Road and Yorkville fame) and Super Fresh Mart are very handy (and I am quite fond of Reither's), but again, they are very small stores. When I lived in the area (until recently), I shopped at all of them, but they did not replace my regular supermarket visits to Loblaws or Dominion.
It never used to occur to me to head east to No Frills or Food Basics. In any event, they are a different type of supermarket.
That leaves the two Dominion stores, on Gould and at College Park. I would say that adding a direct competitor in the middle of those two stores would benefit the locals.
It could be, as you suggest, that the MLG store is not targeted to locals. I don't know. I am not privy to any marketing plans or strategies over at Loblaws H.Q.
Ironically, though, had I not moved out of the area, I suspect I would still shop at Dominion, even if the MLG Real Canadian Superstore opened. With Loblaws busy reducing the number of sku's it stocks, not to mention the problems it has keeping goods on the shelves, I am increasingly finding that Dominion has a better selection of food products than a Loblaws store twice the size.