If Lightroom is working satisfactorily, the decision is yours. When I switched to the creative cloud I uninstalled my Lightroom 5 and installed from the creative cloud application manager. There is absolutely no difference in the program. But the application manager will keep track of updates. And when Lightroom 6 is released it will be available on the application manager.
When I uninstalled Lightroom and installed from the application manager, an icon was placed on my desktop by the installer. I double-clicked on the icon and Lightroom open using the same catalog I had been using. There were no changes or adjustments of any kind that I had to do. So the switchover is painless.
As Jim says.
Also keep your Lightroom License key as it is still valid in addition to the Lightroom CC.
As Jim has stated but if on a Mac the method is slightly different, just trash the current app then d/load via the CC app. But ensure it is registered with Adobe on your ID first... the serial number will be retained there for safety.