Does Bitcoin Core latest version show all receiving addresses previously used before it syncs the blockchain? Or do more show once it fully syncs?
What about versions from 2012-2013?
Yes, it will, if you explicitely look for them. Simply run
I believe they'll only generate more adresses if your keypool is empty/almost empty, so that depends on how much transactions you've done. I'm not entirely sure when it starts to generate more adresses, but i believe there's a 100, or 1000 default pregenerated ones.