If I don't already have a monitor that supports the Displayport 1.2a standard, I'll need to buy a "new" monitor to take advantage of this "free" offering? Proper hardware scalar, standards compatibility, and R&D costs put it on similar footing to G-Sync which also requires a new monitor ....
Yes. Except G-Sync also needs that expensive G-Sync-module from NVIDIA, while the technology needed for Adaptive-Sync displays has been in use by display manufacturers for ages in eDP-world