As an older single BK amputee runner and not of the talent of these guys, I can assure you all things being equal any amputee, unilateral, bilateral, AK, BK or any mix will be slower than an able-bodied athlete.
I advise LR to get an interview with Hugh Herr at MIT for comment. He is a bilateral amputee and even jokes about being able to adjust his leg length so he could be taller than his dates.
https://www.si.com/vault/2012/08/06/106219647/unfair-disadvantage
That said, see this article and look at Leeper's legs in the top picture:
https://deadspin.com/a-double-amputee-coming-off-a-cocaine-suspension-is-sud-1826553854
Where I believe he can have an advantage is by having prostheses that are too long, or 'running tall' as we describe them. This does give an advantage because with the same turnover rate, long legs would cover more ground. Imagine Usain Bolt being 7' tall and still turning over his legs at the same speed.
There is a calculation for the prosthetic leg length, which I believe has been adjusted downward over the years. I don't think Leeper has been measured for this and would be shocked if his current legs were legal for records.
I too dislike people who simply spout off nonsense about this subject, as many have no idea of the different types of amputations and the mechanics of running in a prosthetic limbs.
Where this is all headed for amputees may be changing drastically in the not-so-near future as true bionic limbs were muscles and nerves have a direct connection to the brain moving powered prosthetics will nearly end disability. These athletes will have to compete in an entirely new Bionic Olympics as they most certainly could soon have an advantage over any intact person. I imagine some moral and ethically questions will arise for sure. Here is a great video about what is to come:
https://www.youtube.com/watch?v=Tca5Hd91FOw