The Bitcoin Foundation is paying Devs to work on the core code, so they have a type of control over projected changes.
I do not believe Bitcoin Foundation have control over the Bitcoin code. They may have influence over some changes, but the majority of the devs are still working independently.
The core Bitcoin code (combined with the blockchain) tracks "every Satishi" from their creation to the current address.
Anyone can track every satoshi without Bitcoin core. I would be far more efficient for Governments to write their own analytic tool than injecting such function into Bitcoin core.
to change the code to 'collect' (for the greater good) 25% of all existing Bitcoins and send them to a single address
Then everyone will stop using the new version of Bitcoin core client, revert back to old one.