Article looks like bullshit based off nothing but speculation to me. There's nothing that offers proof or backs up their claims at all. Nobody knows what happened to satoshi, his coins, or even if he is one or more people.
It is very simple to look that up. Look at the first 20 000 blocks on blockchain.info.
There you will see Satoshi's addresses and their contents (indeed mostly 50 coins).
Block 0 (genesis block): address 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa
It has received some dust (and now has 65 coins in it) but never spend anything
Block 1 (first block) after genesis block: address 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX
It has received much less dust and now contains 50.025 coins, never spend anything
Block 2 : address: 1HLoD9E4SDFFPDiYfNYnkBLQ85Y51J3Zb1 and contains 50.00038429 BTC
and so on.
Block 10000: address 1JoiKZz2QRd47ARtcYgvgxC9jhnre9aphv, still contains the 50 BTC and no dust.
Block 15000: address 1KzP9ideELyDMyjg4svrheub7Ttg6W2cdk still contains the 50 BTC.
Block 20000: address 1Gtj5h1u8yZJe32neQZB5C7efP9XeMd9SW still contains the 50 BTC.
...
In fact, I wonder whether the idea is simply not that instead of a total amount of bitcoin of 21 million something, to have exactly 20 million. If you subtract the early coins that don't seem to move, it seems to turn out to be about that.