Why do we have to wait nearly a year to get the weekly cache system where we can get to choose between 3 items?

I'm 100% sure I'm just another one between thousands of frustrared players every week. I've got 3 items corrupted with leech now. The weekly cache was frustrating enough WITHOUT corruption, now I'm not even excited anymore to open a chest that is supposed to be a big weekly upgrade. Why do we have to wait until shadowlands to get the new weekly cache system? They already thought of it, they probably already designed it, and it's probably working in the current version of shadowlands, why not implement now? Why not try to bandaid the frustration players have every week?