I am not sure it is rushing BG3 but it does feel like shortcuts are taken, to make it easier/for budget reasons. The focus so far from what I noticed is pretty much on the Origin characters and their personal story, rather than adapting the 5e ruleset properly/better, or to build an engine from scratch.
Having played DOS2 after playing BG3 as well, I did notice that for all the clunky mechanics and things DOS2 had.. somehow BG3 made them feel even clunkier. Right now, rather than BG3 being Early Access it almost feels more like a big Tech Demo to me.
I'd say it's probably all either budget related or a bug. As much as some would like to allude to Larian not understanding DnD rules, I'm sure they understand them as well as the players or better.
Questions like "Is it worth it to the players to have a proper reaction system?" it will take X hours to add in the game. "Should we have random encounters at camp?" that'll take Y hours to add in the game.
And Larian wants our feedback to know what is worth investing the time in. It makes a lot of business sense to wait for player feedback in early access rather than spend time that you did not need to spend.