Only counsel and upper management for the City, Metrolinx, CN, TTR and any other interested parties are going to be privy to the juicy stuff. At least until there's some agreement in place. I think it's going to be in the dark for the forseeable future, until then we can only rely on a city webpage to remind us that there is a dream.
Months back I posted the results of what I researched *appearing* to show (only later Acts of Parliament or court interpretations could change it) that the City *continues to own* the corridor along what used to be The Esplanade (only part of which is left as a street today). If that is the case, look for massive court battles to erupt as the City takes back claim to those air-rights, let alone ground rights. From my reading, the railways were granted "leases" not ownership, of the Union Station Corridor.
From memory (I'll try and re-find my extensive digging on this a year ago, never had success using the on-site search function here)(I'm spoiled by Google with much more adaptive search algorithms) private land owners each side of the corridor were granted the right to bridge from one land parcel across the corridor to the other, within the terms of the then version of the Railway Act. That might be a slight complication although the general outcome should still be that the City has almost unfettered access to claim a massive swath of air rights.
Last I read, it would take approx a year of legal searching and discussion for the City to state a public position on this. I thought perhaps this was the announcement from their Legal Dep't on exactly that.
We do get a nice picture to look at and get distracted from all the other real issues, however.
If anyone wants to search this string for what I linked and posted prior, the tags "Tri-partite Agreement" (perhaps spelled without the hyphen) and "Esplanade" should show the relevant paragraphs, the legal ones from a provincial statutes record book I had to use screen capture to quote. The province, as is the protocol still, had to barter with the Federal Gov't and Parliament on the City's behalf to establish the law on the matter.
Edit to Add: Somehow I had the sense of mind to copy this into my email records, since I'd sent off much of what I'd found to solicitor friends for comment (their replies were almost all of the opinion it would take court action to re-establish what appears to be on the books, the question really being "in which court?") but here's the major reference, and there's pages on this, so bracket both sides of this link to find the complete relevant section:
https://books.google.ca/books?id=BupHAQAAMAAJ&pg=PA572&lpg=PA572&dq=Esplanade+or+Tripartite+Agreement&source=bl&ots=1q9Pyh4ENJ&sig=B_54nS2NfC0ZCshhgm5qZje8RhQ&hl=en&sa=X&ved=0ahUKEwjzrZ2slM7PAhWo34MKHRFMD7cQ6AEIKDAC#v=onepage&q=Esplanade or Tripartite Agreement&f=false
There was at least one major test of this (these) statute(s) in the courts (SCC IIRC) that confirmed the City's case on this, back in the Twenties I believe. Again, searching this string for what I posted almost a year back will show that all detailed and linked.
I'll continue searching my email records.
See Pg 32 + of this string for more reference
And here's the Supreme Court Case examining the law on the matter, I was off by a decade, but close:
https://scc-csc.lexum.com/scc-csc/scc-csc/en/9855/1/document.do
That's the first page of a 78 page written decision!
THAT is what one would hope the mindless little minions at City Hall would be examining and making a statement on.
In the event (and pardon my becoming subjective on this) I think it's beyond them. And they should realize that and retain genuine counsel to examine.
But I digress....