Keyword scores are the numbers you make decisions with, so they get rebuilt whenever the stores give us a better way to compute them.
Traffic now spreads properly across the range instead of compressing at the top, so a head term everyone chases and a phrase with genuine, reachable demand no longer land a few points apart. Difficulty leans on what actually decides whether you can break in: how strong and how fresh the apps already holding the top positions are, rather than how many apps target the term.
Both formulas were recomputed across the full history, so your charts stay continuous rather than showing a cliff on the day of the change. KEI, which weighs traffic against difficulty, follows from the two and now has its own column in the tracker with a color scale that makes an opportunity readable at a glance.
Some of your keywords will have moved. The new ordering is the one that survives contact with the stores: the top of your KEI column is where an indie app can realistically win.