First of all, we have no evidence that your Edge example was intentional. In fact, we have evidence to the contrary as they fixed it within hours of it being reported [1]
Now as far as your hypothetical, sure they can, but I use all of those services, YouTube, Gmail, Maps, ... on Chromium every day and they do not block nor have they ever blocked any of them.
> And it may even be a quick ‘n dirty deliberate hack to exclude Chredge this way, just so it doesn’t pollute their telemetry / testing of new website features.
That test proves nothing without seeing the Google's code. Feature detection is incredibly slow, requiring JS and multiple round trips. Whereas user agent strings are instantaneous.
Chredge worked for many weeks, then it didn't for a day or so, then it worked again.
Turning the block on was intentional, and turning it off was intentional.
We can only guess at their motivation, and I can guarantee you it was not benevolent given what Mozilla said recently about their interactions with Google.
>How's this polluting their telemetry? Also, how is some random UA NOT polluting their telemetry? It's a horrible excuse, that's all it is. It was fine and then suddenly it became "an issue". It's singling out them, SPECIFICALLY. Nice try.
Now as far as your hypothetical, sure they can, but I use all of those services, YouTube, Gmail, Maps, ... on Chromium every day and they do not block nor have they ever blocked any of them.
[1]https://twitter.com/addyosmani/status/1133782407419613184