The article you provided doesn't back up the claim that playing video games has the same effect on the prefrontal cortex as meditation.

1. It discusses video games that were created with a specific purpose of improving ability to focus.

2. It mentions that researchers have a hypothesis that these games will improve ability to focus.

3. It mentions that there is an ongoing research into what's happening in the brain when people play these games.

I don't see how you can take this and draw a conclusion that video games have the same effect on the prefrontal cortex as meditation.

And your initial claim was broader than that, you said that "prefrontal cortex activity touted by Kelly McGonigal is achieved through any other focused activity", which appears to be completely baseless.