Hey, can someone please explain what may be the consequence for Sumo regarding this DMCA file?
No consequences at all. It's a formal issue that I assume will be fixed soon.
It just demonstrated toxicity and corporate approach of monero development. It would be no wonder if people run away from such a hostile coin to an alternatives like sumo&co that are true open-source.
This idiotic approach monero demonstrated show its fear. The whole thing could have been discussed via email. Are they afraid of quality forks? Aeon that is a copycat and has one but the only dev is coming from monero, therefore no prob although it's code and copyright is a mess.. Now bytecoin will behave in a same way and block monero? I seriously don't get this..
My 2 cents - open-source was a vehicle for crypto launch but as soon as money came to play people are behaving like asses and are forgetting that code is free and everyone can use it, enhance and share.. Kids, don't take the game so seriously. You can't escape alive

Stop blaming other projects if you did the wrong thing... doesn't matter if things could have been resolved via email, issue or whatever ... THING IS THIS SHOULD NOT HAVE BE AN ISSUE AT ALL... abide the rules and give copyright where its due ...
As you copy&pasted everything else, why didn't you just add a file for Sumocoin and let the old stuff as it was ... you even deleted cryptonote-devs out ... they could blame you too... stop attacking the messenger