From what i'm seeing, they have a gag order in their contract until their sales are final.
Basically no one can announce their version until all sales are final with LRG's version, Josh basically states this in his next few tweets attached to the one you posted.
Ok there is a contract, you realise that not only one company is on a contract right? Then why only complain about the one side? The terms were accepted by all parties, whoever those are besides the developer/rights holder and LRG, including the other publisher. The fact that news of the release hit is beyond that point, outside parties are not bound by the contract.
Then perhaps LRG should be more transparent as should others that sign contracts like these.
In order to have something like a gag order in place, you don't have to let other companies have a say in it, first come first served as it were.
So if LRG signed a contract that stated no one could announce the release of any other version, LRG had to knowingly sign that contract that they knew would stop others from talking.
Other companies would then sign contracts that state 'by the by, you're not allowed to talk about this game you're going to release, because this other company got there first'.
So when people were asking LRG if there was going to be anywhere else that was releasing it and LRG said 'no' that must have had some inclination that that wasn't going to be true, since they had to sign a contract that included a gag order against other companies.