There's 3 separate questions here:
1) The legal issue (my post above summarizes the case) as well as further procurement of land (remember that Stan Thomas still holds roughly 800+ acres nearby including around 500+ acres directly connecting the 475 acres that Comcast bought out of bankruptcy).
2) How fast can it be built? Arguably within 3-3.5 years at a maximum if it had to be rushed... but then:
3) When's the optimal timing given other projects: Universal Beijing will arguably be the focus for Universal Resorts in 2021 (or 2022) and then you have the WDW 50th that likely will run through 2022.
If you put it all together, it probably favors the actual opening dates in the year 2023 (which would give Comcast 5.5 years to sort out the legal issues and then get it built while letting Universal Beijing get its year and WDW 50th).
If I had to design an "odds of when the next gate opens", it'd look something like this:
2021: 10% odds
2022: 20% odds (cumulative 30%)
2023: 40% odds (cumulative 70%)
2024: 15% odds (cumulative 85%)
2025: 10% odds (cumulative 95%)
2026 or later: 5% odds
Basically, that's what it looks like to me based on all the other issues; by 2023 at the latest I'd assume it's up and running; with a decent chance of it being finished earlier or later.