That specific statement has five citations and all of them are from 2016 or 2017, when Brexit hadn't happened and so they were merely speculating about possible future effects. So none of the citations supports the claim.

The citations also contradict the statement, "the referendum itself damaged the economy". Instead they admit the referendum's effects were better than predicted by which they mean there weren't any:

"It won't mean Armageddon, but the broad consensus of economists—whose predictions about the initial fallout were largely too pessimistic—is for a prolonged effect"

and

"Unlike the short-term effects of Brexit, which have been better than most had predicted"

Wikipedia is a hopelessly compromised source, you shouldn't rely on it for anything where a left wing activist might have strong opinions because they'll just straight up lie to you, unfortunately. Grokipedia's article is marginally better, but still makes the mistake of citing discredited analyses and making false claims based on them.

If you really want to know the truth about this you have to just go to the core data and see for yourself, because the space is full of claims made by people with a clear agenda.