The Chagos Islands should not be British, but should they even be Mauritian?

I, for one, had never heard of the Chagos Islands before this week. But the International Court of Justice (ICJ) has now weighed in and declared that the islands should not belong to Britain at all.
The Chagos Islands is an archipelago of tropical islands and attols in the Indian Ocean, roughly halfway between Madagascar and Sri Lanka, the largest of which (and really the only one anyone has heard of) is called Diego Garcia. It really is in the middle of nowhere. It has a few fish and coconuts, and the reefs and oceans that surround it are considered a diversity hotspot. But it has no real development, either tourist or otherwise, apart from a joint UK-US naval base which is considered strategic. It is officially administered by the UK as part of the British Indian Ocean Territory.
That, however, is where things get difficult. The ICJ has ruled that Britain illegally hived off the islands from Mauritius (then a British possession) in 1965, just before Mauritius was granted independence, although in fact they paid Mauritius £3 million in what seems to be a bona fide commercial transaction. Anyway, the Brits did not behave very well, and forcibly expelled about 2,000 of the native Chagossian  islanders from their homes, prohibiting them from ever returning, so that the whole place could be turned into a military base. At any rate, whether Britain bought the islands in good faith from Mauritius or not, the ICJ has ruled that it was "an unlawful act of a continuing character". While not actually legally binding, the decision puts a lot of moral pressure on Britain to release the islands back to Mauritius (although what then is to happen to the US naval base? Tellingly, the American judge was the only dissenting voice in the ICJ's decision).
However, when I looked up the Chagos Islands, I was surprised to find that they are actually nowhere near Mauritius. Diego Garcia is over 2,000 km from Mauritius. It is closer to the Seychelles (a bit less than 2,000 km), and much closer to the Maldives (just over 1,000 kilometres). Some parts of the archipelago are within 500 km of parts of the Maldives, and historically the islands were originally settled by traders from the Maldives. So, why, then, do the Chagos Islands revert to Mauritius, and not to the Maldives? Can we expect another ICJ court case some time soon, and another improbable mention of the Chagos Islands in the international press