I have been recently emailing with Goodgame Studios. Here is what i got as an answer:

April 03, 2019, 10:58 +0200
 
Hello Marcin,

thanks a lot for your message. 
My name is Lilly and I will take care of your request today.

I'm very happy to hear you like Goodgame Café so much and are fighting hard to get it back.

Unfortunately, we had to take the decision to take Goodgame Disco, Fashion and Café offline in November 2016. As you can imagine, this decision was not easy for us, as our heart was in the game and we loved the caring community. But unfortunately, the games were old and couldn't be taken care of and supported in a way we would have wished it. 

Also the petition will not help to get the game back :(

I'm very sorry! I hope you will find a new game that you like! 

With kind regards, 
Lilly

So I think this petition is useless, we will not get our lovely Goodgame Cafe back... I'm thinking of closing it and that will be all that we did for this game. At least we tried, what do you think about it?