Has Kindle update policy changed?

[tomsem]

I manually applied the 6.3.1 update months ago, but today I turned on my Fire and it said it was 'updating', as if a new update had been pushed over wifi. I was a little excited at first ('finally! they're fixing bugs!'), but as it turns out, it is still 6.3.1..

The same thing happened with my Kindle Touch a few days ago.

Is this some sort of new policy Amazon is implementing, i.e, 'always push the update even if they already have it'? Or are these distinct builds of the same 'version'? (I don't know what the build id might have been before these automatic updates).

Just wondering if anyone else has had this happen recently.