From the article:
"In the letter from senior project manager Stewart, Cadillac Fairview says it “needs” to begin construction at the East Harbour transit hub in summer 2022 to meet the province’s 2026 deadline for opening."
Any disputes have to take place before summer 2022, or else there'll be a delay (On top of regular delays) in building the thousands of apartments that they're planning (And that many in city hall claim to want in a bid to cool housing). The Ontario line is planned to open in 2030, so it would fit in nicely with that.