The Earth-Sun L2 Lagrange point is not "behind the Moon." It is on the line from the Sun to the Earth, but another 1.5 million km farther than the Earth. Probably perpetually in Earth's shadow (which makes sense, operationally). The Moon has an orbit at a much closer distance and moves around the Earth. They will line up during lunar eclipses.
The Earth-Sun L2 Lagrange point is not "behind the Moon." It is on the line from the Sun to the Earth, but another 1.5 million km farther than the Earth. Probably perpetually in Earth's shadow (which makes sense, operationally). The Moon has an orbit at a much closer distance and moves around the Earth. They will line up during lunar eclipses.
Correct, I could maybe have said it better. L2 isn't slaved to the moon's position, you are right.
It's a confusion. There is a Sun-Earth L2 and an Earth-Moon L2. It would be easy to get them mixed up.