Yoshi's matchups seem a bit exaggerated.
Sheik 9-1
Gay *** chainthrowing in NTSC till 100% or so I've heard, so probably right
Fox 8-2
Big advantage over yoshi seems right, but as it stands now it's equal to falco's matchup ratio, who can be seen as yoshi's worst matchup next to NTSC sheik (trapped in shield complex, gets shine combos easy), so I'd say 7-3.
Marth 9-1
I consider marth one of the more manageable high tier matchups, on final destination dead even, on other stages slight favor to marth. marth definitely has the range advantage here, but no reliable kill moves but the tipper against yoshi. Because of that yoshi can live to ridiculous %. Besides that yoshi has eggs, can double jump through marth's attacks for the nair counter, can dodge an fsmash with his own fsmash, can do relatively well in edgeguarding marth (instant edgehog, dsmash/dtilt), and can do good damage when marth is above him.
I'd say 6-4 marth's favor.
Jiggs 9-1
Don't have the most experience in this matchup, but 9-1 is ridiculous. Probably around 7-3 to 6-4. One of the best things about jiggs, his/her edgeguarding, hardly works on yoshi around <70% or so. Yoshi has projectiles that have a great trajectory considering jiggs mostly moves around through the air. Aerials (mostly bair) are hard to get around, but to combat this somewhat, yoshi has body distortion with fsmash/upsmash, both much larger hitboxes than most people expect.
Falcon 8-2
Both can combo eachother massively, but falcon has his insane speed and it doesn't really help you can't use your shield (both spotdodge and roll are too slow to be of much use, lightshielding is pretty good if you have no other option than shield). Uptilt however does stop almost every aerial approach in it's tracks, and is a great move to start juggling or go to jab(reset) to downthrow. Knee tears through double jump, making recovery somewhat hard, but the same can be said about a falcon recovering low. If he goes high it's a bit hard though to edge guard succesfully (only options really are nair and upair, nair doesnt send him too horizontally with good DI, and upair kills only like at above 150%).
8-2 is probably right (although could be 7-3)