Yeah, because all players just know every bit of information thats in every patch note.
Such stupid requirements. Should just work.
It's probably the only way they could get a fix in, without an extended downtime.
If the sage is not its own item type, and instead derived from another item type, then the only thing that differentiates it is the scripts applied to it. If that's the case, then to fix all of them, it's necessary for every item in the game to be checked to see if it's the right item, and have the fix applied to it.
At a guess, that would take a similar downtime to when two hour downtimes for duped items, some years back. Since the items aren't widely used/owned, you can't really justify that level of downtime.
However, running a small script, on login, on a player character's inventory, is something that can occur on the fly. Rather than having to work through the entire inventory of the shard, you're going through 125 items tops.
It is, ultimately, a best case scenario. Especially since if you're using the items, they'll probably be in your pack, so relogging is something that may happen naturally, making it an effectively automatic fix in those circumstances.