Bought the Lucio bundle today and had a comp with tracer+valeera which would normally be awful on Battlefield of Eternity... But
We absolutely stomped them and the chase potential was unreal..
Lucio is totally OP but not because of his healing, but with his speed enhancing abilities imo.
He can allow your team to absolutely ignore mage abilities easily, he can provide disengages with ease. He can chase and solo some classes which is unreal for a support.
Every game I played with him felt so much easier than any other support, and if it's dual support that can provide some damage like li li or tass than it's GG.
edit: In short, crossfade probably needs some sort of larger c/d, being able to switch on the fly is a bit too much.