Two cases here, the first one being easy and straight-forward…
1) If the installed scenery was already built for SODE v1.3+, then all the files are in the right location and a reinstall of SODE does not do anything to those files. So there is no need to reinstall the scenery itself.
2) If the installed scenery was *not* built for SODE v1.3+, then a reinstall of the scenery will mess up your SODE installation and is not recommended. In this case, I’d look for a scenery update for SODE v1.3, remove the old and install the updated scenery.
Unfortunately, there is no complete list of sceneries that support SODE v1.3, but I think that all the major ones have updated their sceneries to support it. Latest releases already have built-in support for V1.3+ and a reinstall is not necessary in this case as I’ve pointed above in 1).