No, not a legend.
He was (so far) a 1 time title holder who defended his belt in an extremely close and controversial fight, lost his title to the same guy in his next fight, and so far has been a contender generally speaking, but he just had his shot and lost.
So, although right now definitely a huge mark on the LHW division and a great fighter, he is not HOF material right now and unless he does some spectacular things in his future, he won't be remembered as a legend (I assume).
“Anna, my strong, terrifying Anna.” -Cas
"You lack the requisite spine and testicular fortitude to study under me" -Elodin