Hello.
The previous perpetual licenses are valid, and the support and subscription contracts that are in force, remain valid until their expiration date.
So far what you cannot do is to renew support and subscription contracts or purchase new ones with the old licenses. If you need to be covered by a support and subscription contract you will have to switch to the new subscription licensing scheme with its annual cost.
My small and medium sized customers (version 6.X and 7.X) have decided to stay with the perpetual licenses and wait a while to see if it is worth it to move to the new licensing scheme or start considering other virtualization options.