To be clear, while the new CRTC guidelines state that there can be no penalty to break a contract after 2 years, you are still obligated to pay any balance remaining on a device subsidy received when originally signing up.
Replacing contract cancellation charges with device balance is something that TELUS had already implimented several years ago. As such, these new CRTC guidlines won't impact anything in this regard.
Whether or not TELUS keeps 3 year contracts is something left to be seen. Personally I see the 3 year contract as good things as it means lower device subsidy when I sign up or renew (since the total cost of the divce can be prorated over 3 years). It's win win. TELUS get comfort knowing they have me agreeing to remain with them for 3 years, and I get a lower upfront cost to my phone.
As I understand it, when the rules take effect the device balance as well will have to have been repayed within the two year period. The rules as you said do not take effect until Dec. 2nd and will not affect current contracts retroactively so that is why you still see three year terms. Don't sign up for three years now thinking you'll be home free when the rules change.
What I personally expect to see happen is a move towards pricing we see where two year terms are already the norm - more upfront cost for the device. As it stands Telus and their contemporaries haven't really stated how they'll be adapting to the changes. They probably don't even know yet, so I cant see them making any official statement until that time.