+1

They have the right to give their game for free as much as they want to. Faerie Solitaire devs gave away 25k keys at once here on Steamgifts, and a lot more on previous and consequent giveaways. They wanted to promote their new games, and I saw no one from steam stopping them to.

...

1) Being on Greenlight doesn't mean you have a contract with Steam yet - the game is not being offered by the Steam store service or Valve, nor are the games' files stored on and distributed from Steam's content servers - there are no binding agreements yet, except for the agreement to abide by Greenlights' rules; no form of distribution agreement.

2) Whether or not the game is ever offered on the Steam store, the rights to the game belong to the rights-holder, not the distributer, and the person who owns the rights may do anything he damn well pleases with his intellectual property, notwithstanding any precisely outlined agreements concerning specifically ownership or licensing of rights or specific sales or exclusive distribution requirements in any contract that any rights-holder would obviously be a fool to ever sign (signing away your rights in whole or in part for such a small / low cost / low visibility game).

3) Even if the game does get picked by Steam (let's not forget Valve themselves pick what goes up on the store and what doesn't), they are picking it knowing in advance about the free key promotion the devs ran to help get their game up.

In short, you're really not that smart, and if anything, this could lower the chance that Steam will pick this up for distribution - as that would mean they'd be paying for bandwidth and server space; both of which aren't that big an issue on a game that would probably run no more than a few hundred MB, especially for a company like Valve, who already has behemoth colocations - so ample space and bandwidth. Also, if this promised promotion would influence Valves' decision at all, that influence would be based purely on the amount of people in the group (thus lost sales), versus projected sales. If they think enough of the game will be sold (if only a couple of hundred sales probably), it would justify the aforementioned space and bandwidth costs. And any profit is good profit.

So, then, in conclusion, this will hardly hamper the games' chance of getting picked up for distribution, and Valve certainly has 100%, nothing, zilch, nada to say about how many keys get given out for free, unless the dev stupidly agrees to sign some contract specifically waiving their right to do so, or requiring part ownership of the rights to the game by Valve.

Oh and I almost forgot the absolutely plausible possibility that the devs already ran this by Valve, and they agreed it was totally OK - which would also explain one way they could honour the promise. Valve can obviously see everyone that voted for a specific Greenlight game by way of a simple database query, then add the game to peoples' libraries, or even turn over a list of all e-mail addresses the devs should mail keys to.