Murder, she did write, just not in Westeros.
Sadly the rumor that Angela Lansbury was joining Game of Thrones is false.
At the time, it seemed plausible that Lansbury would be joining the cast, seeing that the show is full of British talent.
The rumor began over Labor Day weekend. The original source was a German website for tabloid newspaper Bild, which is described on Wikipedia as “notorious for its mix of gossip, inflammatory language, and sensationalism.”
One thing that is true is that Jim Broadbent ( Professor Slughorn in the Harry Potter franchise) has been confirmed to join the cast.
Season 7 will span seven episodes, with Season 8 spanning just six episodes.
Game of Thrones Season 7 will premiere in Summer 2017, although no premiere date has been announced.
Source: tvweb.com, ew.com