I am at University of Toronto right now. I have only been here for some months but I have seen enough things to get a sense of the "politics" of the place. Also, I've been in many of the world's top universities (Caltech, Cornell, KAUST, Oxford, Stanford, UNAM, and some others with less pompous names); either studying, visiting, working, w/e. I've been doing this for close to 20 years now. I know a lot about what academia is and how it works behind the scenes.
With that said ... University of Toronto is, by far, the most amicable, egalitarian and open academic environment I've ever had the chance to be in. I have several Indian friends I've made during my stay, and not a single time has the issue of caste come up to relevance. Caste doesn't have anything to do, at all, with how this particular University chooses their faculty members.
I know OP is not directly (or is he?) accusing UofT of taking part on this, but someone reading this could easily get that impression since 1) he's using his academic page to publish this "opinion" and 2) he states:
>I had begun to mention references to my caste in Facebook/Twitter threads in the past two years. I was, however, not ready to publicly declare it until <I received tenure (in bold letters)> as it seemed too risky.
So, to all other readers, I can assure you that caste had absolutely nothing to do with OPs election/non-election as a faculty member and I really wanted to set the record straight on what actually is a really nice place that treats all of its members with dignity and respect.