Then they should forgive the Night elves right? I mean, the high elves insisted on continuing magic, but unlike the Shend'ralar and Suramar night elves, they actually taught it to humans, and it is humans recless use of magic that started attracting demons afterall, eventually leading to how Sargeras could subvert Aegwyn a nd her unborn child, that eventually leads to the orcs and the invasion of the legion.
One could argue that if they had upheld the ban, which was in place for the sole purpose of preventing the legion from returning (and not some fan made headcanon of hating the arcane), then this wouldn't have happened. The high elves really have the fault lying with them. Without them, humans would be none the wiser to true magic.
But knowing them, they'd probably blame the night elves for not wiping them out, like the penalty of breaking the ban demanded.