Reported speech question

I work for a small publication that's recently hired a new editor, and there's a edit that this guy has been making in all the copy to come across his desk that's been perplexing me. In any sentence of reported speech that identifies the speaker in an independent clause set off by a comma or commas, he insists that every verb in the sentence has to be in past tense (to match the "said" in the clause). This logic gives you sentences like the following:

- The new law would go into effect next week, she said.
- Bill Gates, Forbes Magazine said, was currently America's richest man.
- Saudi Arabia, he added, had the youngest population in the region.

I feel that these sentences should read "will go into effect", "is currently America's richest man", and "has the youngest population in the region". In a sentence without the commas, you of course do need to match the tenses ("She said that the new law would go into effect next week"), but that kind of sentence seems distinct to me from the ones I listed above.

I've been doing some Googling to try and back up this point, but I'm having trouble finding a rigorous theoretical explanation for why this should be so. Is there a rule that governs verb tense in these sorts of sentences?