I disagree at least on one point - I've also played Dota a fair bit in the last few years, and as for Dota, I think parent might be pretty on the money when they say games are moving away from traditional MOBAs. The format is great, but in its 'traditional' form (three lanes, jungle, etc), there's only so much you can do with it. I think the market is pretty ripe for innovation on that format, and Dota won't be able to keep up when it happens.

I also agree with parent in that 'Blizzard just blew the doors off the market by revitalizing a game format that Valve invented' - I honestly think it's hard to argue that point. Overwatch is conceptually very, very similar to TF2, and must be doing some damage to its playerbase (though I haven't checked any stats on that at all so I might just be talking shit).

I don't play TF2 much these days, but from what I've been hearing/reading, a lot of people in the community are dissatisfied with the recent update and yes, some are leaving TF2 to play Overwatch.