One rumour that has gathered traction via Videocardz.com is that Radeon Boost is based on a technology called HiAgo Boost which AMD acquired along with the company that developed it three years ago. If Radeon Boost is HiAgo Boost or some version of it then it will be an adaptive system to reduce graphical fidelity to preserve frame rate at moments of action, possibly obfuscated by some sort of motion blur, before restoring settings when things have calmed down and demands are lower.
Such a system sounds dicey, conjuring images of a game like Red Dead Redemption 2 momentarily going all Minecraft for the duration of a shootout, but arguably it could be better than either having your settings perpetually low to ensure performance, or accepting that high settings would cause bad stuttering. Done smoothly and unobtrusively this idea has a lot of potential.
We won’t know for sure what the Radeon Boost will do until AMD officially announces it, and then we won’t know for sure if it’s any good until we’ve seen it with our own eyes. However we know to keep an eye out for it now.