Question relates to what you think the rules should be, not what the rules currently are.
Some Evo-legal Yamahas and Husqvarnas came with Twin Leading Shoe front drum brakes.
No Evo Hondas or Suzukis came with TLS front brakes.
You can legally fit a Yamaha or Husky front end to these bikes, but some people prefer not to fit parts from other brands, and would prefer to use later Honda or Suzuki parts on their Evo bikes.
One argument says "it's still got drum brakes, so it's still Evo legal".
The other argument says "that drum brake is from a non-Evo bike, so it isn't legal".
Should the later TLS brakes be allowed, or not allowed?
What about the matching forks from the later bike?
You don't need to justify your opinion, just let me know what it is.
Suzuki RMs got a twin-leading shoe front drum brake in 1983.
Honda CRs (And some XRs?) got a TLS brake from 1981.
KTMs got TLS front brakes in 1984.