Do I need 32GB of RAM for 1440p gaming?

Not yet. Most modern games at 1440p run just fine on 16GB of RAM. You might see a small boost in a handful of titles like Star Citizen or Microsoft Flight Simulator, but for 95% of games, the difference between 16GB and 32GB in frames is single digits. The money is better spent elsewhere—a faster GPU, a better cooler, or just saving it.