^Uh, no. They make frequent references throughout Avatar to the interconnectedness of all life on the planet down to a neural level. The process is even demonstrated between the Na'vi and their riding animals as well as with the Tree of Voices and the Tree of Souls. The implication is that in some way the entire biosphere of the planet is part of a "group mind" that may or may not be conscious in and of itself.
The Na'vi may have personalized this group mind as the "goddess" Ewa, but that does not make an entirely plausible scientific concept into fantasy.