Adding another datapoint: this still can be done. Held business saver tickets after calling 6 different agents. Tried the US, Singapore, and Australian numbers but they all seemed to route to the Philippines center anyways. The key the last time seemed to suggest that I wanted to create a booking and then pay for it later. She looked up the itinerary, confirmed the space and cost, and then held it for 10 calendar days.

Other times I got "checked with my higher authorities" or a blanket "we cannot hold reservations" or "you must book waitlists from the website."