Can't speak for the present, but in my exchanges with WT in Treg, I've gotten email from different addresses so I don't know if one is inactive later or just not the one they used to email me. But I can say that the address in question was at least active as of last November.
As for responses, all I can say is sometimes, even in treg, we'll send something in and not hear anything back, especially if it isn't something serious. If it is big, like making it difficult to even use the TB, I'll usually get a quick response or even a phone call that day.
But for other things, it seems to depend on what they are focused on. Like maybe I send in a report about occasional swapped characters (which hasn't happened in a long time), but they are focused on a bluetooth issue - I won't hear from them. And then, maybe weeks later they followup on my report. Which I always took to mean they were no longer focused on something else.