Project Fear, if you like, was a medium-term prediction, and as a result won't be refuted for a while yet. In fact signs are mixed -- the depreciation of sterling on the markets, for example, is not exactly all positive and has persisted for a month now. Meanwhile most economic news is still for periods leading up to the referendum, not after it.
It's not all about the economy anyway. Already, there have been plenty of stories about UK-EU scientific collaborations being postponed or cancelled, of falls in EU student applications to our universities, etc.
Still, there are some good signs that in the short term the lower value of the pound, etc, will serve to attract some foreign investment (although it makes the inverse more expensive), and there was some good news about jobs recently eg Amazon announcing further investment. It's surely far too early to get out the party hats and so on. Brexit hasn't happened yet.