Worked is probably the keyword there. Perhaps he would have canned it if it didn't give results by now, I don't think he'd know if the current management would do the same. Like I said, I doubt they are going to give up on Clans, Group Ironman, and the useful engine changes for tons of content just because it isn't ready to talk about at this RuneFest when they've been talking about it for years and just started work on it. It seems pretty obvious that Leagues were the 2019 "mode" so if we did see Group Ironman, I doubt it would be until 2020 and they may not announce it until that RuneFest.
Of course I could be totally wrong, but that is still my opinion and I suspect my opinion is more informed than most.