I kinda like the way they're handling League data too. I like that we now only have Challenge data to actually see everything that's Top 8'ed.
So if you want to make a data analysis to discover the % of each deck on Top 8's, you can't use League data anymore, just Challenges. League data serves for you to discover viable decks and have a glimpse of what's viable in the format.
I like this and think this approach makes for more cautious data and reduces the speed people were starting to complain about "dominance". This may result in a less active B&R Announcement schedule for us, which is great.
Vintage was always a format of slower changes, and I believe this is a step in that direction so I like it.