Points to take in the video:
It's not a permanent solution because the fluctuating heat from the die/chip can melt and disconnect the already banged up soldering from normal usage.
The problem that may have been easily fixed through another method that didn't require baking would potentially now be impossible to fixed because of the variable the baking process created.
Different components in the GPU has their own soldering method and material used and baking the GPU for one small part will mess up other soldering due to different temperature curve requirement for re-flowing.