Jon (SHS`) is leaving the project. Another former important member of the team is returning, in a role that is apparently not yet defined. In the topic linked above dhn writes:

Look out for an announcement with the title “A return” during the next few days

As an open source project, albeit with a limited set of developers, phpBB is bigger than any one individual, and I expect that it will go on with or without Jon’s participation. It has survived other notable departures during my tenure as a phpBB user. John Abela (AbelaJohnB) the first MOD Team leader, Paul Owen (psoTFX), the lead developer for many years, and most recently James Atkinson (theFinn), the original founder have all left the project for various reasons.

Am I concerned? No, not really. Jon put his heart and soul into the project over the past few years and deserves a break. One of the reasons I picked phpBB2 so many years ago was the fact that it has a thriving user community, and one person leaving will not change that.

Best wishes to Jon as he starts a new chapter in his life. Thanks for all the Berties.