You can't really say you have won after a controversial issue is resolved and the event it triggers happens.
You have only really won when a significant number of those opposed to the idea accept it and begin to support the new status quo, putting it's existence beyond doubt.
In the case of the reformation it took a century and a half of violent bloodletting before this happened, from 1536 to 1689.
Astonishingly, due to the incompetent and unpleasant way the EU has tried to blame others for the failing of its vaccine procurement, this acceptance of the new status quo by remainers has happened abruptly, almost overnight; instead of taking place gradually over many years, perhaps even a generation. Indeed many have had the courage to say that they got it wrong about brexit on social media.
So yes you are right. Today it can be said that the leavers have won.
The best news of all is that it has, well documented verbal abuse apart, happened democratically and peacefully (although it was a close run thing at times) which those on both sides can take credit for.