Based on what's in the wiki, I don't have a direct quote from John Harbaugh specifically about Malik Nabers' injury — the most recent update comes from ESPN's Jordan Raanan, not the head coach himself. However, here's what the wiki says as of the latest August 11 training camp update:
Nabers is on track to play Week 1 against the Cowboys. He avoided the PUP list and is progressing well, expected to be the Giants' No. 1 receiver (from the Malik Nabers page). This is a big shift from the July scare when a scar-tissue procedure raised PUP concerns.
That said, the wiki also notes that Nabers' recovery is from a torn ACL + torn meniscus — a more complex injury than a standard ACL-only tear. So even if he plays Week 1, his early-season explosiveness may be limited as his legs regain full strength.
On Fantasy Football Today, they noted Nabers was averaging 19.4 fantasy points per game as a rookie, calling him a "Malik Nabers talent" — the upside is massive if he's healthy ().
Bottom line: The org believes he'll be out there Week 1, but monitor his preseason reps closely. If he's fully cleared, you're getting league-winning WR1 upside.