Its not haki bloom imo, its Luffy beginning to figure out how to use his CoC in 1010, and increase his expertise in current chapter. Kaidou said "you gained access to a powerful weapon" (Luffy used his pool of CoC and apply it as CoC Coating) "but you were carried away. Your technique leaves a lot to be desired"
Tldr imo Luffy always has big CoC pool. And in both 1010 and 1026, the main factor is not haki bloom but Luffy figuring things out just like his statement in 1010