The way Dr Becky described it, the principle reason to orbit was to maximise insolation. I guess if there is no "orb" - "it" is a misnomer that any idiot can still visualise. But does it require a mass at the focus to qualify as an orbit? OED 1st definition requires merely a curve (usually closed).

The JWST probably requires more propellant to "circle" L2 than to stay directly at it. Or maybe they have some clever interaction with the moon that stabilises the halo. Or that it is just the nature of a Lagrange point, it wobbles. (discuss).