Well I know that other studios can port games like these Examples:
4J Studios Ported Minecraft to all Consoles like Xbox, PlayStation and Nintendo consoles.
Sumo Digital Developed LittleBigPlanet 3 with other studios like Tasier, Supermassive etc. for the PS3 and PS4
Crash of the Titans did have Ported to portable consoles from Other studios as well.
Isn't it good for them for agree their deal to port Game Dev Tycoon with another developer, while Greenheart will focus more on their original works. So it might be Time consuming or good for them? What do you think from your opinion. Feel free to answer.