They're even keeping GWT alive somehow. That was a major mistake, though. I remember building a large GWT project and the compile times just started getting into multiple minutes. Debugging was hard.
They are not. It's a third party fork that's keeping it alive. It's dead because Google didn't put any resources into it and just threw it out to see if it sticks. Then didn't keep up with the capabilities of JavaScript frameworks and didn't release any proper templates.
It never used GWT. They claimed GWT can be used to build apps like gmail and that was misleading. They didn't write it using GWT since it predated the existence of GWT.