Is it ok to add more than one node to a exist cluster

[dayu]

Hi,
    I have read a warning of not Simultaneously bootstrapping more than one new 
node from the same rack in version 2.1  link
    My cassandra cluster version is 3.0.10.
    So I wonder to know Is it ok to add more than one node to a exist cluster 
in 3.0.10. 


Thanks!
Dayu