What I read at the time also said that it's very hard for a plant to shift from making commercial to residential toilet paper, that the margins are paper thin (pun intended) and so it would take a lot of time and money to retool.
But that wasn't the cause of the problem: the cause of the problem was people thinking "oh I'm not sure about a shortage, better buy an extra pack" (I know we did) for just one week...and then someone posts an "empty store shelves!!!" image on social media...which in turn prompts another group of people to do the same at another store, and then the idiot-brigade scalpers get involved. There's still no actual shortage though! The amount of toilet paper being produced is the same, the consumption rate is the same, people have just changed their stockpiling preference and the rate at which they do is spreading faster then any conceivable supply chain adjustment. But the actual consumption rate hasn't changed at all.
The idiot-brigade scalpers are worth commenting on because IMO there's a second factor which usually turns up: it's kind of fun to "buy out the supermarket" of some good. Like there's a child-like glee of going "I'll totally buy all of it" but most people don't consider that you can do this for any one item in the supermarket for like, $300 on the spot. It's just there's no reason too - partly because it's the most expensive possible way to buy almost anything.
You seem to have entirely missed the point of the comment you’re replying to. The consumption rate of residential toilet paper increased. Have you seen actual commercial toilet paper and considered its texture and, more critically, the size and shape of the rolls? While it’s possible for someone to awkwardly wipe using a monster roll of commercial paper at home, the commercial roll is not really a desirable substitute for residential TP.
Your average supermarket has limited shelf space and stocks to the level that it will reliably clear shelves before new supply turns up, or things spoil.
If a whole much of people just buy one extra pack that week, this can easily empty the shelves... Which then gets posted to social media to imply a supply problem, which then prompts people to increase their buying rate.
There's no solution to this other then education: there was no supply issue, and never was. Any "solution" would be concluding that a supermarket should devote an absurd amount of shelf space to toilet paper, just in case misinformation goes viral again.