Windows May update brings “Hardware-accelerated GPU scheduling” to it WDDM implementation. It also requires GPU hardware/driver support to work. It got some traction and speculation about performance impact but when some benchmarks and analysis started popping out it turned out it’s quite transparent change with no FPS changes… although some benchmarks did noticed performance uplift on like smaller CPUs… and some bugs/regressions.
In case of WoW you can check my benchmarks:
https://rk.edu.pl/en/testing-hardware-accelerated-gpu-scheduling-world-warcraft/
It works, no regressions and for i5-9400F + GTX 1070 there is rather no noticeable effect on performance.
Aside of that - few pre-Shadowlands tips: if the next expansion will launch with VRS and raytraced shadows support you may pick a GPU that support those features. And if you don’t have Shadowlands yet - AMD RX 5000 GPUs can be sold bundled with Shadowlands (not live yet).