"So he published The Myth of the Britannica, showing they'd gone to sleep on the job, having not revised many articles in yonks."

Dealing with information sources that are dodgy because they haven't been revised or are out of date, is something that's been around for ages - but dealing with information sources that are subject to revision by interested parties without any obvious indication of this having being done is something else, and it's a lot more tricky.

It would help if there was some mechanism by which changes were flagged up, and earlier versions were still available.
....................

...that the US-led invasion was not a "US-led occupation" but a "US-led liberation."

I'd say that's within the spirit of Wikipedia. The two expressions are equally subjective statements of opinion.

I'd disagree there - "occupation" is a straightforward term for a situation where a foreign army occupies a country and is in charge of running it. No value judgement is implied. An occupation can well be a liberation, a liberation carried out by a foreign army can hardly avoid being an occupation, for at least some time.