You could be waiting a looooooong time. If the issue only impacts Inscription (which it does) and then only the people on this quest chain (also true) and then only people who will be going back to do this after Shadowlands drops (again, true).
You are probably talking about a maximum of 10% of the people using the crafting system, and realistically only about 10% of those are going to bother enough to go through this quest chain when the new content drops. 10% of the WoW playerbase is a large amount, but 10% of that subset its likely far below their threshold to “fix it now”.
I know where I work, if we had an issue like this, a fix would be years in the making behind a lot of other projects. That is until a bunch of people start complaining and making the development and support teams spend the hours.