User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170321042248/@comment-29963364-20170321230203

Zekram offered Issei (and Sairaorg, but he wasn't there at the time) the option to become a Satan precicely for the purpose of putting a cap on his progress & influence.

Zekram was the guy who spear-headed the Anti-Satan Faction because he and the other Pure-Blooded Devils wanted to preserve what they had after the Great War. Sirzechs, Ajuka, Serafall, and Falbium showed that they were the most powerfull Devils at the time, and their accomplishments were earning them support and influence in the Underworld. So Zekram and the other Old Devils made Sirzechs and the rest Satans to appease the common masses, and serve as "symbols" of strength to the rest of the world. This also served as a kind of "leash" that the Old Devils could use to keep the new Satans from having more influence than themselves.

So Zekram offering Issei (a Reincarnated Devil) and Sairaorg (a "defected" Pure-Blood) the title of Satans isn't a sign of "times changing."