The Big Bang Theory is still expecting next season to be its last even though an official decision hasn't been made

TVLine

“Until I hear differently, yes," showrunner Steve Holland says when asked if he's planning Season 12 as the final season. “I know we have next season, but I don’t know what happens beyond that,” he adds. “And it’s not my decision to make. So all I can do is go forward with next season and make it great.”