I'd say the DK Megaman MU is evenish (maybe a slight advantage for Megaman).
As annoying as Metal Blade can get, in a low/no lag environment you can just dash attack to catch it or super armor though it with Up B and trade. Blocking it lets you pick it up and prevents him from being able to use it as long as you hold it.
As annoying as lemons can be, the fact that they only do 2% and oftentimes don't combo into each other means they don't really do much. They are the epitome of low risk low reward gameplay and as long as you don't get frustrated, they shouldn't really be that big a deal. A successful trade with Down B/Up B or a sneaky aerial only needs to happen like once every seven times you get shot for it to go even.
Crash Bomber is pretty bad once you know what it does. The fact that you can transfer it over to him just by contact means you aren't necessarily forced to block or dodge when it explodes to avoid it. Even if you can't get close to him, all you need to do is air dodge or roll and you get a free hitbox while being invincible.
Megaman's Uair is never really an issue to avoid with how lenient the timing is to air dodge through it. Even if for some reason you can't air dodge through it, you can just drift away to avoid like 90% of any Uair juggle situations. The only time Uair is scary is when Megaman SHFF Uairs at close range.
The most annoying thing about Megaman to me is probably how fraudulent his grab range/speed is. That combined with being combo food in general is a pretty easy way to exploit DK's biggest weakness.
Megaman's spaced aerials and his ability to KO absurdly early with Utilt/Dsmash are what I'm afraid of going into the MU. Every time DK whiffs a move that isn't like Jab or Dtilt, I fear the Shoryuken punish. Spaced Fair, Bair, and even Dair are surprisingly safe and their disjointed nature makes them hard to trade favorably with.
Fsmash is also pretty scary sometimes. When I'm on the ledge or when I am landing, charged Fsmash always seems to catch me by surprise. I am always caught off guard at how big it is, how fast it goes, and how far it reaches all the time. Random uncharged Fsmash is pretty decent in footsies too.
Most of my KO's against Megaman come from edgeguarding and juggle traps. He only has a slow Dair to protect himself from below and an Up B that just delays the next juggle attempt by a couple seconds. Since his Up B has no hitbox, I get a lot of mileage from stage spikes and just intercepting it in general. On stages that don't let him wall jump, you can hit him too far for his Up B to recover from.
As long as DK exercises patience, the MU against Megaman isn't really bad at all. It's usually a slower paced MU, but DK can win in a battle of attrition.