This assumes that Microsoft still has a browser engine division by then. I suspect that adopting Chromium was largely a cost-cutting measure and this division is on the chopping block already.
Sticking to their own engine would have eventually killed both. Hard to get people to adopt your browser if webdevs are not testing sites with it. And webdevs don’t care if your market share is marginal.
I believe the alternative would have been most of the enterprises deploying Chrome on Windows to access their apps. With this move Microsoft might still retain control of the app level. This is valuable because then they can for example provide integrated windows authentication for the apps.
That set of proposed changes from Google looks like one to me, but it's possible they don't to MS.
I was just starting to get that butterfly/stomach feeling for Edge, I don't think I'd ever leave FF for it but Edge was pretty attractive and I started to developed some warm fuzzy feelings for it. My initial revulsion has long since been replaced by a sort of curiosity which had the potential to grow into even more... That chromium news killed it though.
And, oh my god, how many times Google asked me to install Chrome. They are really annoying with those ads which never stop to appear. I suppose that for many users that might be the reason to switch to Chrome, to stop that insanity.
Interesting - I've never seen that in FireFox
The API doesn't let you add to the list of blocked uris outside of posting a new release of an extension. Ouch.
I can only gather that the actual goal is very different from the stated goal.
I have Firefox on OSX already, and it runs smoothly. Unfortunately mobile Firefox (while supporting all those extensions), has a jittery scroll issue on Android, so I use the Chromium-based Kiwi Browser (for night mode) or Brave (for built in adblocking).
I assume, though, that Google will eventually make some change that Microsoft doesn't want, and they'll be forced to fork chromium.
The recent proposals from Google[2] that hobble ad blockers and extensions like tampermonkey might even be enough.
[1] https://www.theverge.com/2018/12/4/18125238/microsoft-chrome...
[2] https://www.bleepingcomputer.com/news/security/chrome-extens...