I've actually been thinking about this for a long while. Could a band replace all of it's classic members (not just original members) and still be considered the same band, if they were working with the blessing of the original crew? If so, does it need to be done sequentially rather than completely? Judas Priest seems interested in going this route to a certain extent, but let's extrapolate for a band we know better.
In 2019, Nicko McBrain retires due to age and arthritis. Although Steve Harris has said that they'd stop if Nicko retires, he instead decides to hire another drummer. In 2020, the band releases a new album, On The Edge of Forever, with new drummer Rufus Taylor (formerly of The Darkness). This begins a quick pattern of retirements, with Adrian Smith retiring after the 2020 leg and Dave Murray having a stroke from smiling too much in 2021 during the second leg of the On The Tour of Forever, which suddenly has new meaning. Adrian is temporarily replaced by Vivian Campbell for the rest of the first leg, but George Harris joins as his full-time replacement in the winter break. Replacing Dave becomes much more difficult, however, when during the auditions Rod Smallwood passes away peacefully in his sleep (Bruce Dickinson quips, "It's the only time he did anything without grumbling."). Fans are already complaining, but Steve decides to go forward and announces a huge double-first - Voyager's Simone Dow will be Dave's replacement. "Australia's basically like England, but with more criminals," said retired member Nicko McBrain. "And they have proper football there sometimes."
But the worst is yet to come. In 2024 Steve Harris is forced to announce his retirement due to longstanding back issues; Bruce Dickinson has a second, and far more serious, bout with cancer shortly thereafter, leaving Janick Gers as the only long-standing band member. Surprisingly, Steve moves into Rod's place as manager and decides that he can continue to run Iron Maiden as manager (possibly the only actual role he might consider taking) and announces a search for a new bassist and singer. Now people are screaming, but some are actually quite happy.
Is this still Iron Maiden, if the original members are behind it?