Neutral B - arrows
Side B - boomerang
Down B - bombs
Up B - spin attack
and then some stuff like the jump attack on his dash attack, or those aerial moves from Zelda 2 as his dair and uair.
Okay but for real, though I do think this post is right, it's no fun. I do hope Champion Link is a new character alongside classic Link, and as such for his moveset I'd probably go with, hm...
Up B - Revali's Gale. He just soars up high and then glides with the paraglider. Similar to Peach's up B I guess, but with windboxes so that everyone caught beneath Revali's Gale also soars along with Link.
Side B - Stasis. Only works in a certain range in front of link (as if he was aiming it forward), and then freezes an opponent for a very short time, allowing them to accumulate any knockback dealt. It wouldn't be too broken because the move could be fairly slow to come out (I'm thinking well upwards of 20 frames), and only freezes an opponent for 1 or 1.5 seconds. Also very punishable if you miss it.
Down B - Remote Bombs. Work kind of like classic Link's bombs, but they only detonate when you want them to, or when an opponent hits them with a strong move or whatever (though they can pick it up too).
Neutral B - Daruk's Protection. Counter, and can also reflect projectiles. This one's too obvious, really.
Final Smash - the Master Cycle of course!
What else, let's see.
Jabs - your average everyday Master Sword combo. Could be finished as either a 1-2-3 or 1-2-Spin Attack.
Utilt - Link just raises a lit torch.
Ftilt - Shield parry, doesn't really need to counter something but if it does it becomes more powerful.
Dtilt - low ranged attack with a spear.
Dash Attack - standard heavy weapon dash attack from BotW. I think the Woodcutter's Axe fits.
Usmash - Urbosa's Fury, just summons some crazy lightning above of Link. Very powerful, but sluggish.
Fsmash - Link throws a weapon forward. Could rotate between 3 weapons like Peach's fsmash, each with varying speed/strength.
Dsmash - Cryonis, freezes any opponent right in front of Link. Kinda like Lucas' PK Freeze mixed with ZSS' dsmash.
Nair - no idea
Uair - no idea
Fair - no idea
Bair - no idea
Dair - That crazy spear attack you need to do to get into the Veiled Falls Shrine. Could spike right at the beginning of the move, and has a considerable landing hitbox.
Grab/Zair - Magnesis. Kind of like classic Link's Hookshot, just different visually. Can snap you to the ledge too, and all that stuff.
Throws - eh whatever.
Yeah, whatever. I kinda ran out of creativity by the end but there you go.