In totality, this isn't completely unprecedented in the industry, but it is is a tad odd. It's a 90% graduation, but it's not a "retirement of the character IP" but of the streamer from activity. Now, part of me thinks there's some projects stretching out over the next several years that her character was already integrated into and it'll be far less work for everyone to need to rework all sorts of things. Looks like any other "all of Myth" merch won't have Ame unless it's a special event she's apart of?
I have a distinct feeling she'll probably pop up either in the background or as a part of any US-based concerts for the foreseeable future. She's probably been the de facto America-based point person on so many things over the last 4 years that we don't know about, it's probably why the CA office has to exist in the first place. I wish her the best of luck in all her endeavors.
And since it probably at least needs to be mentioned because Rrats will run wild anyway, if a bunch of Hololivers are missing one weekend next year and seemingly were at an event that they don't talk about, maybe Ame found her ultimate teammate.