New Reflection 150 260RD - Running fridge while on the road

I know that sounds like a stupid question - but we were reviewing the new rigs manual and it said don't use propane while on the road to run the fridge - That is contrary to the reason we have the dual - Gas/Electric fridge and we have always run our fridge with gas while on the road - this is our 3rd RV and never heard this before - maybe just legal talk to avoid any liability.