Hm. And only six decades till Columbus...or are you butterflying the C-man?
Nope. The C-Man is on schedule. The Aztecs, etc. etc. are still screwed. The new world pandemics all pretty much run on schedule.
The Greenland Norse are on their last legs, and have mostly fallen out of history. If things had turned out a bit differently, the Interchange might have happened earlier, but probably no more than 50 to 70 years earlier tops.
As it is, I rely upon the 'human beings screw up everything possible' paradigm. The interchange is happening pretty much at its last possible period for the Thule, when their agricultural society is all but impinging on the Norse, and when the flow of artifacts and stories has reached a sort of critical mass.
If European exploration proceeds as OTL, Europeans may run into the Thule in Newfoundland by the early 1500s...
Northern Labrador is pretty much the furthest limits of their sway. Directly to the south are the Cree, who they managed to push somewhat, but proved tolerably good at pushing back. They never reached Newfoundland.
Actual contact with the Thule doesn't begin until the first serious expeditions to find a Northwest Passage begin with Frobisher in the 1570's. Follow up expeditions, petering out by 1620, are discouraged by the Thule.
I'm still working out how things shake out in the 1600's and 1700's. Things get really complicated around that time. Gold isn't really a factor for the Thule that far east, and no one's really gotten far enough to enter the MacKenzie/Coppermine cultural area where gold is actively used. But the Thule have a huge hunger for western tools, particularly metalwork and fabric, which are difficult and expensive for them to produce themselves. In turn, the Fur trade is going to be in full swing, and the Thule are going to struggle to control the northern fur trade routes, even as the Europeans are trying for direct access to the southern fur trappers. Throw in the pandemics, which will be coming along, and its going to be interesting times.