Was it known that they left with coir?
Was coir typically used as dunnage in that region, at that time?
Was it known exactly what they left with?
Was it known where those treasures were offloaded?
Is it known just how much coir is under the beach?
Is this coir connected with a possible buried treasure, or was it brought by someone else?
If this was done by Templars circa 1307, does the timeline work out? (Note that some of the Templar "evidence" may have to be thrown out in order for this to work, which in turn means that the theory may collapse...)
As always, we're left with an abundance of speculation and a dearth of actual facts. That's just what I'm saying, and what I've always been saying, and what I'll continue to say until solid evidence or a treasure (which I suppose is pretty solid evidence!) turn up. Once something does turn up, we should then try to figure out how it got there - not the other way around.
I'll concede that a documented find of coconut fibers (that were properly carbon dated) is extremely interesting...but then again, I've also said in the past that I believe that eastern Canada's history is more interesting than we currently know. Neither of our theories prove the existance of treasure on Oak Island. I'm leaning toward a greater Norse presence than is currently suspected.
I'll answer my second question here has a freebie, in order to explain something else. Were coconuts known in the Middle East during this time period? I think so, yes, but they weren't grown there - they were imported at some cost. It would make sense that the points of origin would use such an available and relatively inexpensive material as dunnage for shipping goods to that area, so I can believe that there may have been something of a stockpile there during that time. The question is, were there any people who were sailing to that area in the 13th century that were also sailing to the New World for certain?
The answer is yes, but as you've done your research you doubtless already know about them. I'm willing to discuss them if you'd like, although the trail becomes a bit tenuous at this point. It is a documented trail though, and speculation is only necessary in order to tie up the loose ends. We know that they went to the Middle East and we know that they went to the New World, and they did both during the same time period. I'm personally much more comfortable speculating on things when I'm basing those speculations on facts.