Judy Greer will return for the sequel as Ant-Mans ex-wife, Maggie Lang. Charlie Cox explains the state of Matt Murdock when The Defenders begins. Joe Russo revealed that, yes, the Reality Stone is in Infinity War and that you will absolutely be able to tell each of the Infinity Gems apart. Olivia Munn confirmed to Yahoo! the film is a standalone and doesnt rely of the audience having knowledge of the other films in the series.”]
Source: https://gizmodo.com/why-daredevil-is-no-more-when-the-defenders-begins-1797280151