Upvote:5
Does this mean that active declaration to US Customs (traveler initiated conversation in the form of approaching a customs officer and making a declaration) is now required, as it was seemingly not in the past?
Yes. It was always required. Making a declaration on paper was still an "active" declaration, in a sense that you're declaring and not waiting to be inspected. Now they don't actively prompt you for it (at least last time I used the Global Entry kiosks they haven't), but you're still required to declare whatever is needed to be declared.
In many other countries they have the "red" and the "green" lanes, but you can be stopped and inspected on the "green" lane just as well. It's just you'd be penalized much more if you're found to be concealing something that you should have declared. In the US - it's similar. See 19 USC Sec. 1497 and 19 CFR 148. The duty to declare is yours whether the customs officer prompts you or not.