I've heard tales of Google engineers creating tools and frameworks largely as a way to attract positive performance reviews and enable promotions. That said there projects like Google Web Toolkit that have a long history and well cared for. Perhaps some transparency would help i.e. instead of "this was made by Google" how about "was made by this team at Google for these reasons and here's where we see it going"

And still Google Web Toolkit slowly gets deprecated.

The problem on GWT is that it builds too slow on bigger Apps, while ScalaJS builds even faster. Also the compiler needs to be reworked on lot's of side, I'm not sure if 2.6, 2.7 will handle all these problems.

But I don't think that GWT gets a 3.0. But thats mostly caused by the fact that this is a really really old technology and there are newer technologies which google builds upon. (AngularJS). They replaced lots of GWT Things already (Cloud Console, Google Apps Console, App Engine Console).

Gwt mostly got abandoned. Far better solutions like teavm that we use at Codename One are available. GWT is now maintained by the community and not by Google.

Actually it does mention that briefly in "What are the origins of Flutter?"

Yes that section exactly answers his question.