If you don't have a local replication going on, your thought is correct too. Then there is no point in making it extra complicated.  By the way, did tou notice the "Ask the Expert" discussion which is going on right now? It's about long distance connections and your question would certainly fit the profile for this discussion, so perhaps you'd like to take a look there as well? You can find the ATE here: [URL]
If mirrorview/srdf ports are dedicated to replication, and those ports are members of a stretched vsan that is used solely for replication is there any point using a transit vsan and IVR?  To my mind introducing them both into this config unnescessrily complicates the design. What am I missing?  I can see the point of using them if a host in one site needs access to an array or tape library in another site, but not if the sole purpose is for replication. If a link goes down replication is dead whether the vsan is stretched or IVR is used.  Is it best practice to use a transit VSAN and IVR in every distance extension?
To transit vsan or not to transit vsan