Patti will definitely be there for when Company reopens - how long she will remain is up for question though. She wants the triumph of a major success at this point in her career, and her Joanne is a guaranteed Tony nomination (and likely a win) when things get straightened out.
I'm keeping an eye on members of the decades long running shows (Chicago, Phantom, The Lion King). They all have a handful of people who have been doing it for YEARS who may have taken the shutdown as their sign to either retire or move on to a different project.
I hope Rachel Tucker will return to Come From Away, but I am not holding my breath unfortunately.
"Life is already so dark. If you have got the talent to make it brighter and bring people hope & joy, why would you withhold that?"