Also, a lot of people that leave the bike alone and go to the dealer religiously for every service are riding less aggressively.
So I have to say "your mileage may vary" because there are so many variable aspects of owning, operating, and modifying the bikes.
I think the good news is that putting most of these slip-on mufflers on the bike isn't going to hurt it enough to kill the bike. Fuel injection + four stroke = fairly safe.
I have spent a couple of decades in the vintage scooter scene where people hop up Vespa and Lambretta scooters and I have definitely seen people soft seize, hard seize, and put holes in their pistons while we're at a rally riding. The funny part is that most people do this because they're trying to get to the bleeding edge of lean so their scooter will go 2mph faster than it did when it was in the safe range.
Also, people doing this 'tuning' usually aren't completely in understanding of how to do it right. ie: they MIGHT change the pilot jets out, but most of them just increase the main jet size and almost none of them change out the atomizer tube because they haven't sat down and taught themselves carburetor theory. I've been on rides where someone holed a piston in 3rd gear at easy crusing speed because his midrange carb setting was too lean. Meanwhile if he would have been riding wide open throttle at 80mph he would have been fine all day long.
At scooter rallies, people are constantly locking up their rear tires when the pistons seize in the cylinders. I don't know why other than that humans are inherently flawed into not being able to just leave things alone, set at the factory settings (which never seize the engine.)
Long story short is that I haven't seen these sort of problems in modern motorcycles, but I see it all the time with vintage 2 stroke stuff and -sometimes- with vintage four stroke stuff. I've seen someone hole the pistons of a Yamaha XS650 but that was the only 4 stroke I've ever seen destroyed with lean settings. I'm not saying it's not possible, but I think we're all safe (enough) purchasing these name brand aftermarket pipes for the Ducati Scrambler.