Yes they did and that would certainly have been a possibility, but they were not known to have been in the Eastern Mediterranean much after 1000ad and the coconut fibres are all dated to well after that date. I admit still possible for a few unrecorded Vikings to have been there during the period in question and have traded their lines for coir packed their vessels with coir packing and sailed where? To North America from the Mediterranean or to Northern Europe and without unloading on to North America which all seems unlikely.
But with the Templars, we have a group that we know was based in the Eastern Mediterranean, would have been using coir known to have been used by Arabs during that period. We know a large group left Cyprus in early 1307 (the correct time period) with a large contingent of ships and men. Later in 1307 we know for a fact that many were arrested and many escaped with all of their vessels disappearing. We also know for a fact that in the Atlantic they basically owned a Port from which they operated Atlantic capable vessels and had at least a temporary safe refuge in Scotland.
Still possible of course for the Vikings and/or some other European group to have done the same thing, but if some others, like say Portuguese it would have been well recorded as they certainly did boast of their seafaring abilities.
In My Opinion the coir found on Oak Island and dated to a period just before the 14th century indicates a Knights Templar presence on the Island. I do not premise that they buried anything there or premise how long they were there. If any of the detractors can undue the coconut fibre dating and show that the three different companies that dated it were incompetent or somebody else deposited it there, I will change my premise, untill then!
Cheers, Loki