Yes, the potential negative impact was actually hyped by pro-trade forces. This is evident since before the economy was low and nothing had made it sparkle up until by the pro-trade forces. This was actually a better improvement having grew by 2.3% in the third quarter since it was noted.
The pro-trade forces' opposition of Brexit did not overemphasize it's negative impact. The 3rd quarter numbers that have come in are not final figures and are subject to revision in the future. Most likely this number will be reduced and a pattern of slow decline will begin to emerge supporting the pro-trade argument.
Seeing the U.K. economy grow slightly in the third quarter is only a short-term result of open trade in the previous year. It will take some time for the U.K. to begin to feel the negative affects of their exit. As trade stops and the benefits of it slowly vanish, the U.K. will suffer from this isolationist move.
The Remain campaign made a number of claims about the negative economic impact that Brexit would have on the United Kingdom, almost all of which have transpired to have been false. These claims were made to frighten members of the public into voting to stay in the European Union and were often disingenuous.