I think that one is more complex. So many have been unable to replicate the problem. So it could be specific hardware/software combinations that cause the problem. Add in the usual people who read there is a problem so then have something to blame for their own errors and the water becomes quite muddy, It becomes even harder when all internal audits under change control point to nothing being changed that could affect AF. But then with all complex software it can be something totally in theory unconnected that leads to an issue.
The problem Canon, and all camera manufacturers have compared to connected devices such as phones, is that there is no live and directed feedback. On connected devices there are logs, crash dumps etc that can lead to a speedy resolution, With cameras there is no such thing at present, so it often comes down to to a combination of close code examination coupled with attempts to replicate an issue. With rapid development as we are seeing now with the move to ML, coupled with an ever increasing list of third party accessories I can see us having an increase in the amount of bugs we see as time moves on. Not just from Canon, but all brands. It is getting much harder for working togs to trust firmware updates and this will only get worse. Add in seemingly deliberate blocking of third party kit such as Nikon did recently with some third party batteries and I think many working togs will only update if they really need to. It made me cringe reading of companies updating all their cameras last week while the firmware was available and then being seemingly proud they did so. I sincerely hope it doesn’t affect their businesses. It is fine for a hobbyist like me, but for those with business critical kit it is a different matter. I would wait a few months if that was my business, unless I needed a fix for an ongoing issue. Even then I would never chuck all my eggs in the same basket.