I guess there is an Athletic article that goes into more detail, but I don't have a subscription. Here is a link though for those that want to read it:
https://theathletic.com/2130237/2020...toews-its-sad/
The Score.ca is reporting that it isn't just Toews, but the core group of veterans including Kane, Keith and Seabrook.
https://www.thescore.com/nhl/news/2037605
I guess none of them want to part of a rebuild at this point in their careers.