Jigs, that a good question that is really hard to answer. I can speak to some degree on MS Project but even that isn’t absolute. Factors could depend on what OS you are using, are you or others synchronizing settings online, how are the old versions removed, what add-ins are you using, anything else we don’t know about? MS Project settings “should” prompt you to migrate or keep separate the first time you open MS Project 2016. I would suggest converting one or a few pilot machines/users and testing the solution. In general, Office 2016 should work pretty transparent to Office 2013. I hope my non-answer helps a little.