Was this really unintentional? It was super nice knowing what hotbar slot was selected at a glance while in the inventory. Now the only indicator is the number being slightly brighter white and very slightly larger, and it's kind of hard to distinguish. Could the number of the selected item at least turn gold like it used to?
Yes, it was. The intentionally changed aspect was a Gamepad only problem. If you are seeing side effects on K/M, we can look into fixing whatever might be behaving differently there, but for the record . . .
I should be more clear about what was actually fixed (my bad for not being more specific).
What was happening was that if your current active hotbar item was FAVORITED, and you entered the menu, the favorited item slot would stay highlighted. If it was NOT a favorite item, it would NOT stay highlighted. This was already inconsistent to begin with, but the fact that it was staying highlighted on the favorite item was an unintentional consequence of a bug (and actually resulted in broken inventory mechanics, which is what we were fixing).
That icon over the favorited item wasn't a "feature", it was literally malfunctioning, causing inventory bugs, and inconsistently at that.
Now, as to whether or not that is something we might want to intentionally implement in some way in the future, that is another consideration.