No, the entity matrix has not changed as far as I'm aware. But you're using a newton matrix here anyway, not an entity matrix. And I'm not sure if the conversion function you've posted is correct. The engine uses a different function for conversion from an entity matrix:

pan = (180.0 / PI) * atan2(m[0][1],m[0][0]);
tilt = (180.0 / PI) * atan2(m[0][2],sqrt(m[0][1]*m[0][1] + m[0][0]*m[0][0]));
roll = (180.0 / PI) * atan2(m[1][2],m[2][2]);