I‘ve got an old iPhone in my closet, which I used until one year ago, when I bought a new one.

On the old iPhone, I had WhatsApp with iCloud Backup enabled. However I did not include the videos in the backup.

When I got the new one, I set it up via iCloud backup, and continued my online life and history.

Now I do miss these videos. Now I‘m wondering what happens when I start my old phone which has these videos locally, and open WhatsApp. What will happen? What will happen to the backup? What will happen to the chat history? Is there a way I could like download the messages on my old phone (and be current) while still having the videos, then recreate the backup, turn it off and then having the videos on the new device, when restored from backup?