The feedback you are referring to was regarding if semicolons should be required in class bodies after methods, setters and getters, which didn't appears to introduce any additional hazards at the time. Async, computed property name and uninitialized class values were not heavily considered at the time.
No, it wasn't. The feedback I'm referring to was regarding whether semicolons should be required in class bodies after class fields. I've talked to a lot of people about this specific decision.
... read the whole story at github.com.
perhaps if everything being shoved in class bodies now were on the table during the initial discussions you mentioned it would have been easier to take a harder stance on semicolon-separators-in-class-bodies will be required.