They definitely don't have the ankle protection of the newer style boots with a pivot ankle. If you have a tendency to hurt your ankle in a crash I'd buy the best boots I could find, it's unlikely they'll be hiking boot comfortable but that's secondary to hurting your ankle again. I've given this allot of thought over the years and came up with some personal conclusions that are just my opinion and based on my experiences.
I grew up racing MX wearing Full Bores that were all leather and low on the ankle protection scale, at the time we didn't know better and that's all there was. For dirt bike riding I wear expensive boots that have the typical well protected ankle. My DS riding is at a 60~70% level compared to dirt bike riding and I don't crash much DS riding because it tends to be remote areas so I ride appropriately. That doesn't eliminate the risk but I'm not convinced the other style are the ticket for safety. A couple situations I know of directly concerning highly protective boots comes to mind. In one a friend was riding Lockhart Basin alone (not smart) but he's a great rider that does that stuff all the time, this time his ecu died on his 450. He was wearing MX boots and had to walk out, he make it 2 miles before the blisters forced him to remove the boots and wrap rags around his feet due to the pain. The other was watching a friend get a torsional (twist) break of his tibia wearing a $500 set of top of the line Alpine Stars. Both are ancidotal but to add insult to injury, after they removed the pins holding this guys leg straight he required knee surgery. Highly protective boots are no guarantee you won't have a serious injury to your leg in a crash because they tend to take out any give at the ankle that allows a rotational twist to be spread over the length of your leg and focuses it at your knee and fib/tib. By design the ankle rotates more laterally then the knee does without injury and most of the riders I know who have required knee surgury from a off road crash were wearing highly protective boots. I'm not convinced you not trading one risk for another, but in the case of a large bike with hard bags there's no question very good boots are an necessity. I don't ride a bike with hard bags anymore which was the one situation I felt under protected with leather boots. Not saying the new style doesn't offer more ankle protection but to me that doesn't eliminate the risks, it just moves it away from your ankle. I'm not trying to justify leather boots and I'm very much aware of the risk factors associated with them. I wear a neck guard when I ride dirtbikes but I don't on a DS bike, it's all risk assessment and one person's risk's aren't always the same as another's. 50 years of MC riding has taught me that most injuries are the riders fault and one should protect themselves appropriately based on their skill level and when that fails the cards land where they land. Just my opinion.