Personally I think it's a great PR move by Valve. Battle Royale is the hot new thing and it'll pull in a lot of players, most of which will probably quit when the next BR game comes along, but some might stay because they enjoy the game. I think in regards to "being scammed by buying the game earlier and now it's free", does it really matter that much anyways? The game was only like $10-15 before anyways. Besides, most people who bought the game before F2P probably have single items worth 50x what they bought the game for, so I can't think they'd be that angry.
I don't think the update is that bad. I just wish Valve would pay some attention to other potential major esports and moneymakers *cough*