Unmistakably. From start to finish. I'm not kidding.
Watch it, and you'll see it. Surely, people are already discussing this. I did read one review that broaches it: "This movie is really about finding a partner for life" -- but to pretend this sells the movie short on poetry. It is very specifically, and very obviously, about heterosexuality.
"Eve" (of course it's "Eve"), pregnant with life, reminding a now-asexual society of its "directive", ultimately bringing children back to earth, with their own joyful directive, to bring order to earth through their own fruitfulness and works of restoration.
Wall-E is a lonely, hard-working Adam. He models masculinity through-and-through, by sacrificing self in order for Eve to be what she was made to be, and do what she was made to do. Others want to take the life growing in her and toss it down the garbage chute, in the name of protecting their lives of convenience. (Does this ring a bell?) But Wall-E, a true man, will protect the threat -- the life inside Eve, for which she was designed -- at all costs to himself.
None of this can ba an accident. If you view this as the typical eco-sermon, you didn't really watch the movie. Wall-E is about male and female, re-creation, and the putting-back of Things-as-Intended.
It's so obvious that I'm sure others have written about it. I saw the movie yesterday, so I'm only beginning to pay attention.