I wonder how long the diet soda manufactures have been working on this, and preparing for it. I would not be surprised if they already have some thing ready to go to replace it with.
First time I was in California, visiting partner and their family, their mom saw the California Cancer Warning of Doom label on a restaurant, and wanted to know why they couldn't simply not allow the substances known to cause cancer.
One of those substances is alcohol, and this place sold drinks.
Unfortunately I know people who drink diet coke like it's water. If somebody ate bacon at that volume they wouldn't live long enough for cancer to get them.
Also the number of ppl having bacon at every meal is small. The number of ppl drinking diet soda - and consuming diet anything else - multiple times per day is significantly larger, at least in the First World.
In my market in Minnesota, Diet coke with "plant based sweetener" is being sold in small quantities. I'm sure it's a market test, and probably good timing based on this too.