To answer your questions:
1.) You must be confusing Louis Leroy and Pierre Le Roy as Louis Leroy is not mentioned in the article. Pierre Le Roy and Louis Leroy are neither from the same family nor connected otherwise.
2.) Pierre Le Roy was one of the most important watchmakers ever and invented the detent escapement.
3.) The escapement used by L.Leroy today is not a detent escapement but a different kind of direct impulse escapement (it is mentioned under "other ideas" in the article). By the way, L. Leroy itself does rightfully not refer to its escapement as being a detent escapement.
4.) A natural escapement (as used today by UN, Ferrier or KV) is more complex than the direct impulse escapement from Pellaton now used by L.Leroy. The Pellaton escapement only needs one escapement wheel and one pallets (basically like the swiss lever escapement). A natural escapement needs two escapment wheels which need to be connected togehter and a complicated pallets.
As a general remark, I am only expressing my personal, technical opinion and I did not want to be negative about the new L. Leroy movement. Every new movement is great and worth to be applauded. I just thought that some Purists might be interested in some historical and technical background information. I like to have an historical approach of novelties. It put things into perspective.
Best,
Goldenlutin