Any exile from the Norse area who isn't on the run will take any tools and live stock that they can, And pigs do very well in most environments.
Pigs don't do well in marginal environments where they destroy pasturage that cannot regrow quickly. By the 13th century, pigs were gone from Greenland and Iceland. But if the POD is back in the 11th century then importing pigs from Norse colonies to Vinland/Markland is very possible. They would butterfly the flora, though. Especially in Newfoundland near L'Anse aux Meadows where "trees" are rather small. I remember little tiny fairy forests when we were up there.
There is evidence of more extensive contact between the Greenland Norse and the Dorset/Thule around Baffin Bay. I attended a lecture by an archeologist from Parks Canada at the Smithsonian back in 2000. She said that when she'd checked on the artifacts dug up from Dorset and Thule sites from when the Greenland Colonies were vital, every single site had at least one Norse artifact. Some of those were from a shipwreck but others were probably trade goods or good will gifts. So there was certainly contact between the cultures up North.
What was the disease load of the Iceland/Greenland Norse back then? Would it have been as devistating to the North Americans as the small pox?
ULTRAGOTHA