has to do with the hybrid graphics of the MSI Katana:
https://wiki.archlinux.org/title/MSI_GS66_11UX
By default, this device operates in Hybrid graphics which works completely fine, but one of the key features of this device is mux switch. In short, it allows physically wiring NVIDIA GPU to the display, which eliminates the need for the integrated graphics processor and resulting in improved performance.
MSI only provides Windows application (UWP or ZIP) to switch between Hybrid graphics (Intel + NVIDIA) and discrete graphics (NVIDIA) mode
It seems that Salix must now run the intel video chip in the absence of nvidia or nouveau