The talk about opening acts that inevitably happens before a tour is always funny to me. There are very few metal bands that are “too big” to open for Maiden. There are plenty of cases of established headliners making the rare exception to tour with Maiden because Maiden has one of the biggest draws in the genre. The only bands I can think of that would actually be too big for Maiden are Metallica and possibly Guns n Roses.
With that being said, it seems like nepotism is the way to go for Maiden. They don’t need another act to draw crowds to their shows and they like to promote what their kids are up to. Some of the suggestions are super cool, like Blind Guardian or even Avenged Sevenfold, but I just don’t see it happening. Personally, I still regret not getting to see Ghost open for Maiden in 2017.