Drive removal as a Backup

My WD mycloud mirror with raid was attacked by ransom ware, all files encrypted,
Was able to get decryption software and key so all files restored now. If I remove one of the drives and put it in my fire safe and replace with a new drive, would the data on the removed drive be usable and could I use this drive to rebuild the raid if the same attack of ransom ware was to happen again. So basically using this method as a backup scheme.
Hope this makes sense any help appreciated.