Not necessarily.
What you have to do (either way) is:
Define your Things again (if you don’t use textual defined things) and
adapt your addons.cfg (if used) to have the “1” at the end for 1.9 bindings.
Don’t forget to save your conf and userdata folder and copy it back to your new installation.
I personally would do a fresh new install to get rid of all the old stuff (but that is only because I don’t have deeper insights into the operating system) and a new fresh install is done within - hmmmm - one or two hours 
Or use openHABian … I don’t have any experience with that but from the comments it looks very stable.