Oh man.... honestly, for real, as a DK main, Falcon is one of my hardest matchups.
I think the trick for Falcon is that you gotta go offstage and edgeguard DK with aerials. Since all DK can do is either...
1.Airdodge, which can be deadly for DK if he's too low (because of his recovery) and falcon's aerials are generally pretty quick and you can get another one off and hit him afterwards.
2. Nair, which is... pretty bad and would probably not beat out Falcon.
3. Fair, which can work, but it's slow enough that the Falcon can see it coming and avoid.
4. Side-b, which is the same situation as fair.
4. Up-b, which has invincibility and great "priority", but has a lot of landing lag if you use it high, and can probably be spiked if you try to use it low. Also it might be able to be beat by a Falcon dive (not sure)
Also DK is a huge target for knees and nairs and falcon dives and all sorts of stuff.
I'm gotta say it's.......... 50/50
Only cause it's Falcon, who has so many other weaknesses, and DK outranges him
But it's a pretty good matchup
you just gotta get the knees
About a month or two ago at a tourney I was playing a friendly set against Ally's snake, and I won.
Then later on we had to fight in the actual bracket, so he switched to Falcon. he 2-stocked me! :o