This is what I did:
As I have a new laptop, I first downloaded my previous version(2014) in my case everything pack into my laptop full install from hd

Then I downloaded my new 2019 version UltraPak into the same folder so I got all my real tracks now from 2014 to 2019 now that said if you only upgrade to plus pack yes you’ll only get the new real tracks that are included in that pack, but you’ll still have your older ones as long as your downloading to the Same bb folder

One thing to note that I found out once you download everything, and you open up the app... in stylepicker you have to regenerate the styles so it picks up everything you have

I hope this makes sense

Biab 2019 ultra pack
Dell laptop I7 running windows 2010
Midi keyboard
Roland BR600 8 track recorder
Sonar X3 producer
flstudio 20