Rebuilding an app by copying the folders?

I’ve an app which seems to have multiple problems with the ios and android build processes. I think it related to a large time gap between me first building the app and node, ionic and cordova updates.

I’d like to just take the code and put it in a fresh folder and start again but I’m sure there are some bits of code that will not come over.

If I use “ionic start myApp blank” can I just copy over my old www folder?