@Gabriel33, I may be misunderstanding what you say but whether the file name is the same as the alt text or the alt text is the same as the file name, that ends up having the same outcome (unless manual steps are taken, as I describe). Accessibility checkers check to see if the two are exactly same and if they are, it gets flagged.
I confirmed this by uploading new pictures into a Canvas page. One file is named "screenshot001.png" and the other file is named "this is a screenshot of my second monitor.png". For both files, I did not change the automatically generated alt text that Canvas provides, which is the name of the file. The accessibility checker in Canvas flagged both pictures.



For the second flagged "issue", if I manually remove the file extension at the end of the alt text field (in this case, a PNG file) the flagged issue is cleared up because the file name and the alt text are no longer exactly same.
I believe that is what you were talking about (while, at least in my opinion, not as clear) when you said "The ".jpg" at the end is still an issue, but it is much easier to clean it.".
I hope that clears that up for what we were both saying and for anyone else looking for a way to name pictures and deal with alt text.
-Doug