The two current Shaw satellites (Anik F1R and F2) are currently about halfway thru their projected life of 15 years. Shaw will likely continue to use them until they time-expire...at least another 5 years, I would think. The question is, what programming are they going to load on or move to G1? They are not saying for now. I think, at this point, that it's safe to say that whatever they decide to leave on F1R and F2 will continue to be available in the south and whatever they put on G1 won't.
It should be noted that Anik G1 is not dedicated to Shaw and is actually mostly focussed on South America. Shaw has leased 16 transponders on G1, not nearly enough to carry all their programming.
All that to say, let's not panic just yet. Optimist as I am, I'm hoping they move all the******I don't watch to the new sat and leave the few channels I actually watch on the old ones.