Restore new phone with previous phone iTunes/laptop backup

I recently lost my iPhone 6 - and am trying to restore the new phone with my last manual backup.

I plugged in my new phone and it immediately asked me to update mobile software update (as it is Apple Music launch today). In doing so, is it possible I restored the manual backup with a clear new phone with no content on?

I am unable to find the previous phone's backup on my iTunes.

Any help would be appreciated.