Short answer: No
Long answer: Where Metaknight has few, if any, meaningful weaknesses, Fox has weaknesses that are actually pretty fatal. Metaknight has the longest range (on a kit of almost entirely disjointed attacks), the fastest attack speed, one of the fastest ground speeds, the best recovery, the most airtight frame traps, and one of the smallest hurtboxes in the game. His only quality that could be even remotely be termed a weakness is his underwhelming overall knockback stats, but given his absolute dominance of the offstage game, this is less an issue for him. With all of this taken together, only a handful of the cast could even fight Metaknight, to say nothing of beating him consistently.
Fox, on the other hand, has two flaws that give a universal path to beating him which is certainly difficult, but which the majority of the cast can exploit. Yes, he is one of the fastest characters, with the fastest moves, some of the best frame traps, and some of the best KO power in the game, but his weight and fall speed make him very susceptible to combos from the majority of the cast, and his recovery (while strong) is one of the most fragile in the game. Incidentally, he actually has pretty cruddy disjointedness on the majority of his moves, compared to many of the characters he competes with. While most of the cast has no solid answer to his neutral game, almost every character can kill him with a smart combo and solid edgeguard. This is not an option against Metaknight.
But it goes beyond that. Fox does not have any unique capabilities that have single-handedly warranted specific restrictions in the game's ruleset. Metaknight has not one, but two such capabilities. One of them is literally broken; It is literally a flaw in the game's programming that allows him to circumvent the game's built-in rules--the game cannot handle it.
First, Metaknight has, far and away, the strongest ledge game in Brawl. He has a fully invincible ledgestall, complimented by ways of attacking while ledgestalling that only a handful of characters have the tools to counter, and then only if they get a perfect read, and have frame-tight execution. And these are only his strongest options from ledge. His ledge game is so strong and full of viable options that he is the only character that actually warrants Brawl's ledge grab limit. All other characters' stalls are limited in scope, and their counters have lower execution barriers. I don't think it's an understatement to say that if Metaknight were banned, the lgl wouldn't be necessary.
Finally, if nothing else here has convinced you that Metaknight is an absurdly overpowered character, then consider the Infinite Dimensional Cape. A flaw in the coding of Metaknight's downb, Dimensional Cape, allows Metaknight to become completely intangible and invisible for a time interval of the player's choosing. No move that can be accessed in competitive Brawl can even interrupt Metaknight's IDC. A ban was put in place on the technique, but it breaks one of the cardinal rules of bannability in gaming: discreteness. You can say the option is banned altogether, but there's no discrete point where the IDC separates itself from the much harder to detect Extended Dimensional Cape. You could band Dimensional Cape altogether, but at that point, the argument goes, it makes more sense to ban Metaknight.
This kind of discussion just doesn't happen with Fox. He has, far and away, the strongest neutral game in Melee, but his flaws are universally exploitable, and unmitigated, and he doesn't have any option that circumvents the game's rules to gain an almost insurmountable advantage.
