Re: Can I Merge WhatsApp chat history between two iPhones
It is possibilty, but you would have to backup the current phone and do restore on the other by using itunes or icloud.
Correct. But as you probably know, restoring from backup would wipe your current data with those in the backup. So this method could only be used if you have a very new target iPhone. otherwise, it is not recommended.
If you don't want to lose any data on your new iPhone, or you can download a 3rd party program called Backuptrans iPhone WhatsApp Transfer from the following link to help.