Pre-release gameplay is primarily there to fuel the demand for pre-orders. As I mentioned in a previous comment on this article, this is a vestige of the days where limited supply of video games was more common (due to physical media shortages, unknown demand, and the desire to have a bit of word of mouth and exclusivity drive some of the marketing) - with digital distribution for practically all games, unless you want a super special limited edition, there is no reason to pre-order - wait for the game to release and watch some YouTube/Twitch of the game and make up your mind, as you have said.