emveepee i965 is the vaapi driver. For intel iHD of "media-driver" package or i965 of "mesa" is used.
The i915 driver mentioned is the intel graphics kernel driver name. LE "xorg-xonfigure" package use the kernel name to choose a X11 config file if required.
Now to the confusion:
The current intel mesa Gallium3D drivers since 21.1 are named i915 (!), crocus and iris. They are chosen according to the GPU, a paste /var/log/Xorg.0.log will show the one used.
Old mesa legacy driver are named i915 (again) and i965 (but not the vaapi driver). They are still available in the mesa-amber branch, the i915 may be named i915g too.
:-(((((
Edit:
PS: is the pci=noaer still required?