Sure, it might decrease the property value of an adjacent house in very specific circumstances, but there's so many other factors involved with that and usually new development is an indicator that your area is desirable and sought after, which almost always means higher property values across the board.
The fact that these projects are being built in Belgravia is proof enough that being wealthy and throwing money at stopping infill isn't going to work anymore, at least with this current city council. And believe me, Glenora is going to see a lot more densification along Stoney Plain Road soon enough with the VLW being built.
Interesting way to phrase that! Trust me, these buildings aren't a threat to the wealthy residents of these areas. You can be assured that they'll still be relatively expensive and targeted towards a wealthier demographic of buyers/renters if that puts your mind at ease.