Actually, "previously thought" is 100 billion stars. That being the case, the new estimate of the Milky Way's size would be 150 billion stars. Elite Dangerous's version of the milky way, with 400 billion stars, is more than twice that size already. So, no, even if new findings add 50% to the size of the galaxy a couple more times, ED already has it covered.
Edit: Actually, I wouldn't be surprised (very thrilled, but not surprised) if at some point in the next couple of decades, ED's galaxy model turned out to be ahead of its time, and the galaxy DID turn out to have 400 billion stars after all. Hell, it's happened before--when I was seven years old, I told my mom that I thought every galaxy had a black hole in the middle of it. Simple kid logic: planets orbited suns, what would galaxies orbit around? Black holes. Science caught up in another seven years, when I was just getting into high school...
It's a value that is rather in flux apparently.
So FD aimed for the upper limit to make sure they did not miss any.