The only thing about what Yulmheric (sp? On my phone) says is that he is an iffy witness. The elementals being unwilling to "suffer" the presence of "such a creature" could just mean they don't allow them in the Twelveswood rather than that they accrue woodsin by being within its borders (i.e. instant Greenwrath as opposed to a gradual build - of course that could also mean they just get all their woodsin at once  ).
On the other hand, the person in question HATES dragons and firmly believes them to be evil. We now know this is an inaccurate view of dragons perpetuated by a corrupt and deceptive Holy See. So it's possible that he's just saying what HE believes to be true about dragons (after all, why would the Elementals suffer the presence of evildoers?).
Just my thoughts.
On the other hand, the person in question HATES dragons and firmly believes them to be evil. We now know this is an inaccurate view of dragons perpetuated by a corrupt and deceptive Holy See. So it's possible that he's just saying what HE believes to be true about dragons (after all, why would the Elementals suffer the presence of evildoers?).
Just my thoughts.