Noob Q: Drive Expansion

[cyberdunks]

Here is my current configuration:

Stripe 1:
932GB WD
932GB Seagate

Stripe 2:
596GB WD
596GB WD

I realize I have no redundancy in the NAS with this configuration but it is not needed as I maintain an offsite cold-storage backup as well as a local hot backup.

I used the "Expand to Volume" option on the second stripe and added it to the first. My question is, if I add additional drives using the Expand to Volume option, will the data on the other 4 drives get wiped out?