I guess if you are an expert at inventing grievance you can project it into the most unlikely places.
The reason why flight attendants open the cans of soda is to control costs.
They have been doing that for decades, long before a possible slight to muzzies could ever have been conceived of.
I don't know of an occasion(if you ask nicely first) that any flight attendant wouldn't give you the whole can.
But that aside, the airlines would prefer to make 2 or 3 cups of soft drink out of every can they open.