Microsoft is releasing "Edge for Android" and it uses Chromium. That is bad for the Web.
It's bad because engine diversity is really essential for the open Web. Having some users, even a relatively small number, using the Edge engine on Android would have been a good step. Going with Chromium increases Web developer expectations that all browsers on Android are — or even should be — Chromium. The less thoughtful sort of developer (i.e., pretty much everyone) will say "Microsoft takes this path, so why doesn't Mozilla too, so we can have the instant gratification of compatibility thanks to a single engine?" The slow accumulation of unfixable bugs due to de facto standardization will not register until the platform has thoroughly rotted; the only escape being alternative single-vendor platforms where developers are even more beholden to the vendor.
Sure, it would have been quite a lot of work to port Edge to Android, but Microsoft has the resources, and porting a browser engine isn't a research problem. If Microsoft would rather save resources than promote their own browser engine, perhaps they'll be switching to Chromium on Windows next. Of course that would be even worse for the Web, but it's not hard to believe Microsoft has stopped caring about that, to the extent they ever did.
(Of course Edge uses Webkit on iOS, and that's also bad, but it's Apple's ongoing decision to force browsers to use the least secure engine, so nothing new there.)