Nope. The file data is open within the browser context, and from there the app can decide what to do with it - which may entail uploading it, but doesn't need t

Nope. The file data is open within the browser context, and from there the app can decide what to do with it - which may entail uploading it, but doesn't need to be. The same way you can open a file in photopea.com without uploading it to their servers.