I think you're absolutely correct in your interpretation of the data in terms of the redistribution. Redistribution went up hugely from 1976, and particularly during the 1980s and into the early 1990s. Around 1994 it peaked, and there was a reduction in the scale as a proportion of the amount redistributed after 1994, though this has levelled out over the last ten years.
I think the reason historically—I'm not making any comment in favour of or against it—that this happened was that the redistribution in the late 1980s and early 1990s was being funded by deficit financing by the government, and in particular by borrowing by the government. Canada reached a fiscal crisis around 1995-96, and there was definitely a cutback of transfers to provinces and presumably of some of the services that are involved in redistribution, and that had an effect on reducing redistribution.
As I say, it's been pretty stable since then. It's a question of whether you think getting back to it would justify doing so through government borrowing. I don't think it's a good idea, because it's unfair to future generations. It takes you back to asking what you do and how you fund it.