Commander Legends has been fully spoiled: https://scryfall.com/sets/cmr?as=grid&order=spoiled
The card numbers reach at least 722 but Scryfall only lists 595 cards. Either their counting algorithm is screwy or we're still missing over 100 cards.
EDIT: Never mind, it looks like they're still loading them. It now says 604.
DOUBLE EDIT: A number of hours have since passed and there are now 718 cards, so if the highest card number I saw is indeed correct then four are still missing as of now.