Maiden have definitely promoted the setist ahead of a tour before, especially on history tours. The original SBIT announcement pretty much gave away the entire set (including songs that weren’t obvious for the theme) and Maiden England had a comment about 2/3 of the songs on the original video being present. They’ve also dropped hints about what songs from a new album they’ll be playing (The Talisman and Great Unknown come to mind).
As far as this tour goes, I think there have been a few hints and a lot being misinterpreted as hints. I’d say FTGGOG is a lock. The press release mentioned surprised from recent albums, the band still stands by that album, and the song hasn’t been played in ten years. It ticks every box. I also can’t imagine why they would choose that of all songs to use during a promo for what is supposed to be a greatest hits tour.
The other two likelys are Flight of Icarus and Be Quick or Be Dead. They have to do at least one deep cut from the 80s and Icarus seems like a reasonable choice. Honestly I never thought it would ever be played live again, but it’s also the sort of song they go to when digging for rarities (think The Prisoner and COTD). Be Quick or Be Dead is one that I’m sure will be played again before they retire and I still think a Donington dvd is coming this year, so something from that period is going to have to be in the set.
Everything else being interpreted as hints is probably wishful thinking and a good way to be set up for disappointment.
As for the rest of the set, songs like 2MTM, RTTH, etc are all locks. I think those clamoring for Blaze songs should brace for disappointment. Even if Maiden didn’t shun the Blaze era as much as they do, there just isn’t enough room in the set list. For the Greater Good of God is going to fill space in the set that would’ve been for The Clansman 15 years ago.
Overall I’d expect this setlist to be a cross between SBIT and Gimme Ed Til I’m Dead. In other words, mostly predictable but a pretty decent selection from each era and one or two deep cuts (songs not played by this lineup). It’s the first tour in quite some time where we don’t really know what to expect so that at least is exciting, but I think we should also temper our expectations so we’re not disappointed when it turns out to be a pretty standard set for the most part. If FTGGOG and Icarus are played, that’ll be enough to make it worth it even if the rest is stuff that has already been on the nostalgia tours.