Crative Cloud: sharing files with clients via link, I want to update the file without sending a new link, is it possible? We share a PDF production catalogue with our clients to organize the correction loop, client needs to zoom to view details, is this p

Yes, sabKY, it is possible to do this with the Send Link feature in CC Assets.  The client won't be able to zoom into the PDF file to view details from the CC Assets site but you can give them the option to download the file and view in Acrobat directly.

Here are some additional reference materials on Send Link:

Creative Cloud Help | Share files and folders

Thanks,
Elba