Totally - I'd LOVE to see the stats at the loss of office space around Yonge/Bloor, Yonge and Sheppard as companies migrate into the defined core. The reality is that those secondary nodes (Bloor/Kipling, STC) never really took off as office nodes. The only success seems to be Yonge/Eglinton which has developed as a node for some tech companies (Facebook, LinkedIn).
Also ttk77 - tech companies (like cisco") are moving in to the core - but their office floor plates are tiny. Like Cisco took 15,000 square feet - these aren't major movers and shakers in office space needs. Nice to have them - but they aren't occupying buildings like 156 Front.
So Yonge and Bloor / St. Clair / Eglinton / NYCC ... are fairly stable markets that have very low stock available, but don't see a lot of new action. So I actually don't think many moves happened from these locations to the core, a few did but probably had some of that space leased back.
Most of the growth in the core can probably be broken down to:
1) Expansion (and now probably more relocation) of traditional FIRE industries ... i.e. the big players.
2) Smaller / medium tech / media companies in the fringes of the core. Most of these are new entrants to the market, so not relocations, just new players, some are American companies.
3) A lot of institutional (i.e. schools / health care).
But there's been little to any 905 -> 416 migration ... and that won't change.
Amazon recently set up a new development (this is real development, not marketing) lab downtown ! So things like that are great, they already had a presence in Mississauga, which still exists (note again the lack of a move), but rather they expanded into the core. Hopefully more of this will happen.
Another thing I've been thinking about; So we know most of the American HQ in Canada are located in the 905 (mainly Mississauga) but there are some big exceptions (some of these are Canadian companies):
McDonald
Home Depot
Both located around the 404 / Eglinton area. I wonder what these companies will do - I'd wager either stay put or maybe move to the 905. But part of me wishes to see something like Coke, i.e. relocate to the fridges of the core (where its affordable).
This Great Gulf development (on the other side of the gradiner east) I think has potentially to attract such tenants ... but I'm really not sure there are enough of them to go around, unless you get the likes of those in the 905. But once your in the 905 its hard to leave