It's going to be quite a while. At the Brooklyn event, it was suggested by UA management the first plane would be delivered in late 2025, and introduced into service in early 2026. So to me it sounds like they won't do any announcement until the plane is delivered and they see what it will take to get it ready for service. And of course they'll need three planes to have consistent SFO<>SIN service on one flight pair, two (or maybe three?) for SFO<>LHR.