I find it funny more than anything honestly.
Oda gives every motherfucker under the sun who is vaguely considered one of the all time greats a sword. Roger, Shanks, Xebec, none of them guys turned their blade black.
Xebec is EXPLICITLY a confirmed swordsman this chapter so it by the way don't matter if people wanna be delusional and claim it is STILL up in the air if Shanks and Roger are. Xebec, much like Oden, is 1000% a swordsman and FAILED to get their sword to black blade status.
Even if some wanna resort to cope about "well, we don't KNOW if Mihawk made Yoru black" why does it matter? Unless people wanna be delusional and deny the biggest Chekhov's gun setup ever, Zoro IS gonna blacken his blade, so he by default is gonna surpass Xebec.
Its over. The "sword-piece" IS REAL and any and all deniers? Dont cry, your "goats" are just not the light years ahead of EOS Zoro you always claimed they were. Its nothing to be ashamed at! Shanks still the second greatest swordsman alive right now, that something right?