Most journalists don't have a technical background and don't know how Unicode works. Plus round-tripping through 7bit ASCII is lossy to characters you may want to keep (accented loanwords / names, non-english text) and doesnt prevent all the attacks in the article (providing text with slightly different spellings / word orders / etc). 7bit ASCII also has invisible control characters of its own in the 0x0 - 0xF1 range...

an American journalist handling English text, maybe.

7b ASCII is so passé that “roundtripping” through it would be very naïve.

so good opsec requires some trade-offs just as say MAC has some disadvantages compered to DAC