I don’t think they did. I think they were all hoping (Nicko included) that he would see out the 50th anniversary tour too.
IMO I think Nicko has realised quite recently, in the last couple of months maybe, that he has to hang it up.
That’s why I firmly believe this new drummer is only in place to fulfil the run for your lives tour. Once that’s done I think the band will sit down and make a decision on their future, see how all the remaining band members feel. There might be one or two others that might be feeling it’s time to hang it up.
For now, all I’m expecting for the future of Maiden is one more tour and one more release, a live album from the future past. If I get anything else like a new album and/or the band does decide to carry on after the 50th anniversary tour then I see that as a bonus. Right now I think this is the beginning of the end for touring Maiden. Not trying to be negative but it has to end sometime and going out celebrating 50 years would be the perfect way. Plus some of the band members will just go off and concentrate on side projects, others will retire and enjoy the fruits of their lifetimes work.