Not a requirement, but ideal.

In terms of permissions and schema changes, any non Clustered environment should do the trick, as long as you exactly recreate the same permissions you have on Pro on Dev (database and instance level).

Having said that, a Clustered environment is clearly different than a regular SQL instance. Patching, for example, is different. And taking the SQL instance down to test DR scenarios and coordinate with developer(s) will also be different.

I personally have a small VMware Cluster (running on an SSD external drive) where I test simple things. It is virtually impossible for me to accommodate all my user databases there but I can test simple things like adding or removing disks prior implementing on Pro. Same goes for patches.