It's that faded out text that's up at the top right of the game pages when you're playing a character on Dwilight. It currently reads, "stable". I remember noticing it myself last week and thinking it was strange, but then forgot about it.
Actually, now that I've just checked, it also says the same thing on Beluaterra.
That has nothing to do with the islands, but with the specific pages. Most all pages are stable versions, even on testing islands. There's a few testing pages only available on testing pages, mostly related to sea travel iirc. That stable/testing/war in the top-right corner is relevant when reporting bugs.
So the character status page I presume Chenier was looking at, only has a stable version, used on both stable and testing islands. Dwilight and BT are still testing islands.
