They still probably lose out on some revenue until a replacement is in stock. Having a working lens is always better for business than getting reimbursed to buy a replacement lens. (That's the nature of the business, though.)
LensRentals do all possible repairs internally, so I suspect that the downtime on an expensive lens like that is minimal if possible. Roger mentioned on the photography subreddit that the aperture replacement was a $200 part and 3 to 4 hours -- it only took so long because it was that tech's first time replacing that part.
He mentions in the article they rented out “thousands” of lenses. I’m guessing the few lenses they have to repair because of this is barely over their normal repair load.
It's like denying you murdered somebody when you sent the police the murder weapon with your fingerprints in the victim's blood. Unless you're OJ Simpson, you're going to jail.