Hi Joaquin,
During re-protect, vSphere replication does not delete the disks from original protected site and instead it will use them as seeds.
How Site Recovery Manager Reprotects Virtual Machines with vSphere Replication
Status would reflect as full sync, however it does not transfer any data at this stage. It performs checksum operations against existing disks to determine which blocks are out of sync and then only replicate recent changes. vSphere Replication must read the entire contents of both the source and target virtual disk files. This operation can be very time consuming and is a expected behavior when using vSphere replication.
Refer this question 'What are the replication and synchronization types in VMware vSphere Replication?' at --> vSphere Replication Frequently Asked Questions (FAQ) - The current version of this doc has moved to: https://storagehub.vmware.com/#!/vsphere-replication/vsphere-replication-faq
I hope that helps
