All one has to do is read the original EA and just see how grossly oversized it is (which I think is a good thing for future growth - otherwise you end up with the disastrous Canada Line scenario where the 40-metre "trains" and platforms are pushing ultimate capacity even now - and may be over-capacity too soon.
I must not have seen those tweets.
Those centres have become more residential than I think they originally anticipated.
I think in the longer term it will work. Though the answer to the then controversial 1990s discussion about which gets built first (Eglinton West, Sheppard East, or the Relief Line) seems to be that they should have built them in the complete reverse order (Relief ... Eglinton ... Sheppard). With a possible downgrade of Sheppard to LRT.
I'm a bit concerned about the intermediate-term capacity of the Ontario Line - though the 90-second headways go a long way to achieve that - about 33% more trains, for 2/3 the platform length - but now with 80-metre platforms instead of 100-metre, I fear they might have not allowed for future growth beyond the first 2 or 3 decades. Perhaps we'll have a Relief Relief line one day. Though I'm not convinced that the current projects will provide enough relief for the Yonge portion of Line 1 - I can see needing another line (perhaps express!) adjacent to it.