I just think it’s neat that Apocalypse remembers his time as Murshid En Sabah Nur and as a free-loving rebel. It fits in nice with what Moira has said was stopping him from joining with the others due to his “primal state” at the time. While he hasn’t completely let go of his hardline “Survival of the Fittest” stance, I think his experiences during X-Men: Black, Disassembled, and Age of X-Man did help mellow him out a bit.