Gasoline with ethanol gums up and clogs the small passages in carburetors very quickly when sitting.
Does the bike have aftermarket exhaust and/or high flow air filters? I can see no other reason to re jet these carbs. The OEM jets provide plenty of power and decent fuel economy. I would question the quality of work done on the carbs. Just in general, most shops do lackadaisical work when "rebuilding" carburetors.