That only makes him officially President elect, and not even then really, since their votes are not counted until January when the President of the Senate opens the tabulations from the electors of the several states. Then he's officially President Elect. He doesn't become President, officially or otherwise, until noon on January 20th.
The ignorance of the Constitution by the blogger knows few bounds.
Just makes my blood boil, watching him stand behind that podium saying “President Elect” and nobody calling him on it.