Herman, I know we all wish things would stay the same but both Don and Olli made their choices for their own reasons. I'm sure they'll be flattered to read what you wish. Amin's announcement thread https://www.photographerslounge.org/f17/changes-forum-moderation-team-5061/ was a way for everyone to find out about Don's and Olli's decisions, which just happened to come at the same time. I think that by thanking them and letting them both know how much they've helped us individually and as a community is one of the best ways of we can all say thank you and let them both know we care.
Of course, it's wonderful that both Don and Olli will stay involved here as much as they can. Life can become busy and being a moderator and/or an administrator can be demanding at times.
I bet moderating this forum is cake compared to other forums I've been on. This forum is very civilized compared to others. As I did in the other post, I wish both Don and Olli the best and I hope they continue to contribute as much as they can.