Exit polls are sometimes inaccurate these days but even in this prediction, if the result is close to this prediction then this is a triumphant failure of everyone trying to "Stop Brexit".
That's democracy folks! That's what happens when you try to stop it, but many don't like the result, so let's have a re-run!
Even when there’s nothing to suggest an election will be close, you predictably get a “polls tightening, anything could happen now!” narrative in the days before the election. I assume those stories get a lot more clicks.