it's possible but it's going to take at least a year to build the building, another year or so to install, and another year to qual (these are ballparks).
Not to mention they have to staff the thing, train the staff, etc.
All of those things can be parallelized. It's one thing to say "opening by the end of 2023 is unlikely", but to say it's impossible is unnecessarily dismissive.
You can’t parallelism those... you need a building to install tools in it. You need the tools installed to qual them. You need the tools quaked to qual a process...
From personal experience I would posit scaling semiconductor manufacturing as 10x to 50x harder than getting a process flow to work in a development fab. Ramps are absolutely killer.
While I'm also optimistic on Samsung's ability to execute some version of this plan, those things can't be parallelized. You can't set up a complex water delivery mechanism until after the building is completed and the cleanroom has been built to spec and tested, and you can't calibrate the gigantic ASML machines until after that.
That seems like a reasonable timeline, which means the fab will be online by 2023, just like the article says. Mass production won't start until 2024, though.