The X-Men and the Brotherhood learn their next destination is the Savage Land as Beast carved its name on the floor of the mansion. But when Apocalypse attacked him at the mansion, Beast was tossed outside; he didn't have an opportunity to carve anything.
Although Beast adresses himself as the one who betrays the team (the traitor in Destiny's vision), the real traitor was Angel who was transformed in Archangel by Apocalypse after been captured. Beast was already part of her vision as the one who dies.