I know all beings — past, present, and future — but no one knows Me. The asymmetry is the verse's whole substance: Krishna's knowing is total; the world's knowing of Krishna is none. The reason was given in 7.25: yoga-maya veils.
Shankara reads the verse as the structural consequence of the maya-frame.
Krishna knows all beings across all three times; but no one knows him in truth. The asymmetry is not accidental: those bound by maya lack the very instrument by which Krishna's essential nature could be known. The verse is the Lord's own statement of the condition that the chapter has been mapping.
Madhusudana reads the verse precisely. Because maya is entirely under Krishna's control and his jnana is unobstructed, he, the all-knowing Parameshvara, knows all past, present, and future beings — moveable and immoveable — without exception. Yet no one, bewildered by that very maya Krishna wields, knows him, except the one whom Krishna himself has made known. The exception is the seed of 7.28-30.
Ramanuja reads the verse as a lament.
Krishna comprehends all beings standing in past, present, and future as objects of his constant anusandhana; yet among those very beings who might know him — the One who has descended as the universal refuge — not a single one takes shelter. The opportunity is open; the recognition does not come.
Shridhara grounds the asymmetry in a principle: maya, though under Krishna's shelter, cannot delude its own sovereign; it only deludes others, never its ashraya. The Lord is not subject to what he wields; the wielded does not contaminate the wielder.
Madhva concentrates the verse into a polemical point: the jiva's incapacity is absolute and intrinsic; only Hari's grace overrides it.
Vallabha reads Krishna's sarvottamatva through the unobstructed jnana-shakti: he knows all three-time beings; not one being knows him as Vasudeva, the one who descended to grant universal liberation.