This means the film will come after Avengers 4, which is set to be released in May 2019. The untitled Avengers movie has an awful lot to resolve, and— spoiler alert, though Infinity War has been out for long enough now— it has a lot of characters to reincarnate.
While Chadwick Boseman’s Black Panther is technically dead, he can’t afford to be gone for long with a major sequel in the works. Boseman’s contract apparently covers five films. He has appeared in only three, meaning he will almost certainly be back.
Marvel producer Kevin Feige has said that Wakanda will become an "anchor point" for future films, and that "some character's stories are just beginning."
The release date has not been announced, but the upcoming Disney film schedule reveals that unnamed Marvel movies will come out in May and November of 2021. Mark your calendars, just in case; this is definitely going to be worth the wait.