Screenshots, autosave, and other features could still save them if the recipeint wanted to.
Or rather, that they are only as private as your relationship with the recipient.
Disappearing messages arent new.

Christian Wiediger / Unsplash
Disappearing images are new to WhatsApp, though.
As such, these View Once messages might encourage a false sense of security.
“Do disappearing images, messages, and voicemails really protect your privacy?

And it doesnt end there.
“WhatsApp stores this data (encrypted) for a few weeks on its servers.
Thats because the media in the message is only “view once” for the recipient.
On WhatsApps back end, the image or video behaves much like any other.
For instance, a disappearing imagewill be backed up as long as it remains unopened.
That means a picture could be restored from a backup, even if it has already been viewed.
Its a lot to understand, even for the technically proficient user.
And what about the children?
But even then, WhatsApp recommends only sending these sensitive messages to trusted individuals.
In the end, View Once could be more trouble than its worth.