Papertrail doesn't have to exist in public as far as I know - and mostly relevant for things they probably should be very careful about tweeting about anyways (yes, I know, "everything is securities fraud", but that's a key point), which is why Musks tweets you reference elsewhere became relevant: Since he's not supposed to publish financially relevant things in non-official channels first but he kept doing it, Tesla declared his Twitter as an official channel for notifications.
How is this any different? His tweets quoted in the article are literally representing himself as a cloud flare employee (the CTO even) to the public. I fail to see any difference between a public tweet discussing cloudflare business and a post written by him on their website (or a press release). It would be different if he didn't discuss company business in Twitter, but at the point of saying he will look into customer support issues in response to complaints about the company, it certainly seems reasonable to assume that his tweets represent the company.
For example, at no point on HN have I even stated who my employer is, much less responded to a customer and said I would take action on their behalf. The reason is that, once I did so, it wouldn't be unreasonable to assume that anything I post under this account represents a company position.
(In part) Because Tesla told investors in a November 2013 official filing: "For additional information, please follow Elon Musk’s and Tesla’s Twitter accounts: twitter.com/elonmusk and twitter.com/TeslaMotors" [0]
