Hi,
there is no such limitation on the number of users that can be registered or use the SAS VA environment, as far as I am aware of. On any license for SAS Visual Analytics as a solution, on distributed or non-distributed versions.
Anyway, your SAS account manager/representative should be the most appropate person to answer your question.
Something different, but not related to the license, is how many concurrent users can your system handle before decreasing on performance, but this is a different story and more related to the sizing of your system.
I hope this may help you.
Best regards,
Juan