At the very least, receivers usually have a 500 lb max rating without a WDH. Maybe you *could* get away without one but may find it tows better and driving is more comfortable with one. A basic round bar WDH doesn't cost much and isn't hard to set up and unhook/hook up.
Our first TT was 20' and had dual axles and weighed 5,000 lbs fully loaded. I wouldn't get a single axle trailer unless you were weight restricted and towed with a small SUV. Note that factory dry weights should be ignored and when shopping, go by the GVWR and use 12-13% for tongue wt. Then take it to a scale after you own it.