I thought that Darkest Hour was a safe bet for this tour, being an Adrian/Bruce ballad in the vein of Coming Home, but apparently Maiden thought differently. I don't see them replacing TTM, since a) it's a Gers/Harris song and those have always been safe since BNW, and b) it has the jumping interaction in the middle, making it one of the better received new songs.
Don't see them playing Sea Of Madness either, especially not replacing CIPWM. The latter is a rather comfortable song for Maiden (which is the reason why it got included, other than being a classic single and representation for SSOASS), while the former is a rather challenging song that didn't even survive the entirety of its original tour. If they'll change the setlist, it's going to add simpler songs like Wrathchild, not make the setlist even harder for them.