I don't care that they are charging for it. I am anti-DNDB exclusivity. That's all.Disney put several series of TV shows in the MCU on their premium streaming service, some of which introduced whole plot points and new characters referenced in later movies. (Wandavision and Dr Strange, Ms Marvel and the Marvels). Essentially, it's DLC for the MCU.
This is no different. The Mortuary is literally the first place you wake up in the included module. They overdeveloped the area due to that and rather than let it go to waste, they put it on Beyond (as in extra, it's in the name) and opted to make a few bucks off it.
Frankly, this is a nothingburger. It's some extra material for anyone who wants some additional material. The problem people are having is that WotC didn't give it to them for free and they didn't get it in the format they wanted. Guess what? I didn't get to watch Wandavision free on ABC TV either.