I cant speak so much to their views on RV owners (they do claim to welcome us on their corporate website though). But as a former vendor that has delivered to local Walmarts in a "big rig", I can tell you they are very strict about trucks NOT being allowed in the front of the stores. There are always designated "truck" entrance/exits...usually behind the stores but sometimes down the outside edge of the parking lots depending on the layout.
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)