On has been the default state for lane assist on each of the four vehicles I’ve owned with the feature and, to my best recollection, every rental I’ve driven as well. The system shouldn’t be doing very much…assuming the driver is doing their job keeping the vehicle centered in the lane. I‘m usually unaware of it until I have need to “hug” one side of the lane.
Edit to add, Chevy’s Quick Start Guide and Owner‘s Manual for the Malibu (I chose 2022) don’t give any indication regarding the default state. The instruction is: “To turn on or off, press the /

\ Lane Keep Assist button on the steering wheel.” There is also the warning, in both publications, that the system isn’t an “auto tracker” — you need to steer and control the vehicle. When the feature is on the
Car between the lines symbol (that I did my best to recreate) will appear on the dash. There’s a bit more detail about
how it works in the full manual, but use is pretty much “drive as you normally would.”