Iron Maiden, from a marketing standpoint, is a dream of a brand in most aspects.
Not just musically, even though they still at retirement age are producing material which gets people super excited.
I just find the discussion of musical direction through the years a bit tiring. The music industry is weird. It's well documented that bands whose records failed to perform or which failed to reach the heights of previous efforts were put under gigantic pressure in the 1980's. A lot of people depended on their success for work. Record companies had a lot of say in most stuff. On the other end, there are stories like George Lynch and Michael Wagener (confirmed) running the guitars for a million dollar record through a cheap Fostex casette recorder to get 'crunch' (which by the way, worked - the Under Lock and Key guitar tone is glorious), hiding the process under a blanket when the executives came looking.
To my point, unless there is some serious discontent within the camp (not likely at this point) no one will confess to what happened between any change of direction. The only well-documented case is firing Blaze to get Bruce back and no one would ever say that was a bad decision, wherever it came from.
But please let's not pretend there aren't market forces likely involved and accounted for in most decisions made. The only completely free artists are the ones in their own bedrooms doing it for fun.