The is no need to doubt that disagreement, because Itachi did not allow Sasuke to use Amaterasu.
The reason Sasuke has Amaterasu is not because of Itachi. However, before Itachi died, he implemented a safety measure on Sasuke so that when looking into Obito's eye, Sasuke would have released the Amaterasu. Which is why Itachi's MS pattern was seen in Sasuke's eye during that scene.
Sasuke later awoke Amaterasu on his own after learning the truth about Itachi.
i caan agree to upto 95 percent of this argument
but we will nevr know if sasuke's eye was accustemed to it or something like drug used to ripen the fruit early (get what i mean)
also itachi could have also implanted the justsu to the eye and when sasuke awakened his mangekyo , as his eye was already alloted a ameterasu it developed the skills to control it which if sasuke had to develop on his own would might have taken a few more years coz he would need to spam enough of it
on the whole blaze release is sasukes skill , no matter what people everything else including my point i gave is all speculation
sasuke can use ( the hell can spam) ameterasu hence it's his tech