The irony is that the article takes pains to describe what a computer is. Now, the only way to read the article is on an online version, and you obviously must

The irony is that the article takes pains to describe what a computer is. Now, the only way to read the article is on an online version, and you obviously must know what a computer is in order to read the article. You're unlikely to find old back issues of Playboy in a library. I know what you mean, a more solid use would be if the article had said 'computers will never take off' and now the article is availabe only on computers. Whether it's an amusing coincedence or hard core irony as you describe, I think it's fair use of the term.