We do not allow external sharing so all sharing is within the origanisation.
I have a PPT document that I have a link to in my onedrive, if I share this link with a colleague, and they open it (they have permissions to open), all they get is one of the images from the slideshow:
If I openthe url (so it goes to the original file) then share the file with the same user, it automatically opens in the powerpoint app. This is what I expected the shared url from my onedrive to do.
NOTE: If I share a onedrive url of a XLSX file, it gives a preview wanring then opens in Excel app once Open is clicked.