Do Opera still bundle Flash with the installer?
I remember they started doing this in the late 1990s but I never kept track whether they stopped or not.
It seemed a good idea to keep the plugins up to date and patched, but was a bit of a waste of bandwidth if you were only downloading a bug fix version that contained the same Flash plugin.
But now we live in the age of automatic updates, Opera & Co could all update Flash only when a new version is available. All disable-able in the preferences, of course so that no mission critical web apps break.