Or is it purely a precaution to save people from themselves?
Given the fact that WhatsApp is a Facebook company, and how VERY trustworthy FB is, there is no doubt that this little problem with have absolutely no effect on the user population. FB users are blind sheep.
Now, reading the linked article, it appears that using WhatsApp to 'delete" messages does not work on iPhones. This is because Apple refuses to let FB (WhatsApp) access to the photo stream with permission to delete anything.
To repeat myself, given "how VERY trustworthy FB is," it is a dang good thing that Apple refuses to trust FB to dive into core iPhone data sets@