Yes, and overall task-based code has been a basis for many APIs since .NET Framework 4.5 (2012), earlier async patterns existed before too. It is not in a froze

Yes, and overall task-based code has been a basis for many APIs since .NET Framework 4.5 (2012), earlier async patterns existed before too. It is not in a frozen state either as each release sees improvements to asynchronous code execution (overall improving ThreadPool, reducing size of state machine boxes, experimenting with alternate underlying implementations like green threads experiment, the learnings of which have been carried over to runtime task handling experiment which will massively reduce the async overhead when it eventually finds its way into mainline runtime).