In general, for sure. Only some big bands have managed to change their style and have their fans follow them. For most a different band would make the most sense. And I am only guessing about Turisas, but they probably should have done so, but it was probably more comfortable to make money with the established hits and name. Starting something new is not easy, after all.
If the musicians are already famous from one or other particular band, then they should easily pull up a strong fan following for their other projects too. Just look at how many people look up the large number of random projects of Speckmann even if say they had found out the band "Master" first.
