Agreed. This is fiction. A mere 500 pages isn't going to exhaust the toner of a printer installed specifically to recieve faxes all day, every day.
And there being an actual printer is even less likely. Even back in 2008, it was almost impossible to find an actual fax machine, even though businesses had fax numbers, they stopped needing machines.
Yes, absolutely this is fiction. It's a combination of his fantasy of how he'd like to "get back at the system" and also it's written to be clickbait ("poor helpless disabled guy gets back at the evil system trying to keep him down")
I'm sure he deals with a lot of crap every day and I'm sure there's a grain of truth in this, but it's pure make believe. But it probably made him feel better writing it and he probably gets some clicks and some followers, so in the end it was probably a reasonable tradeoff. But anyone who thinks in 2026 that an office (government, private corp, etc.) has a stupid 9600 baud paper-eating fax machine spitting out pages is not living in the real world.
And there being an actual printer is even less likely. Even back in 2008, it was almost impossible to find an actual fax machine, even though businesses had fax numbers, they stopped needing machines.