To date, the unique PF number system has not yet been implemented, but I hope it will be done soon by the end of this year. With this system, employees won't have to generate a new PF number every time they start a new job. Instead, they will have only one unique number to provide to their new employer, and the PF amount will be transferred to that account.
In your case, the employee can choose to either withdraw their last PF amount by filling out forms 10C and 19 or transfer the amount from their previous organization to the new account by filling out form 13. The choice is up to the employee.
Regards,
Pankaj Pujari