Deyis II.
Bland scrubbed Deyis II in 501 because a local parasite had jumped to humans causing a slow wasting death while also triggering enough endorphins to make the victim extremely happy while they withered away.
Bland visits Deyis again in 620 and describes a world "... urbs burned to glass, vast stretches of empty terrain punctuated by clouds of radioactives, skies darkened by cascades of dust."
Deyis II is the location of one of the portals to the Primordial City in Knightfall.
Deyis II is the location of Outpost Alpha, MegaTraveller Folio Adventure 2. That adventure is set during the Rebellion and features a biosphere healthy and diverse enough to produce parrot dragons and previously unsuspected sophont race.
Whether the portal survived the scrubbing or not is debatable, but the Deyis of the MT simply cannot exist. Six centuries isn't enough to change the world visited in 620 into the world featured in the MT adventure. Six million years wouldn't be enough.
Agent gets more and more curious.