I've just looked online, and it looks as though it is two years from date of cancellation, not last date used:
Fans of the Marvel Television series recently canceled by Netflix who hope to see the shows revived on Disney+ may be out of luck.
variety.com
It will all just depend on what the use of the word "appear" means... Can they film before this date and just not air publicly?
Therefore...
Iron Fist/Luke Cage/Heroes For Hire/Daughters of the Dragon would not be able to be used until 19/10/2020 (Iron Fist was cancelled on 12/10/18 but both Danny and Colleen were main characters in Luke Cage S2, therefore Danny, Colleen, Luke, Misty and Claire would not be available until 19/10/2020.
Daredevil would not be able to be used until 29/11/2020 - ruling out Matt, Foggy, Wilson Fisk and Dex until then.
The Punisher/Jessica Jones would not be able to be used until 18/02/2021 - ruling out Frank, Karen, Jessica and Trish until then, unless anyone else appears in Jessica Jones Season 3 whenever it airs
Means that we are already through 27% of the time until LC/IF could air, 22% of the time until DD could air and 11% of the time until TP/JJ could air.
Given the fact that JJS2 was picked up in January 2016, but didn't start to film until April 2017 there would be no reason why Disney/Hulu couldn't pick up the rights/actors now and then film when they have time as they couldn't air/film before the above dates anyway.