As you know, McCree left Echo alone at the end of Reunion. So didn’t you ask yourself how she got to Winston? Flying? Pf, she did it with more style…
I’m trying to lighten up the mood for people that are sad that anniversary didn’t come as early as they expected and just in general. 
She’s doing it to be like McCree on Ashe’s motorcycle, she looks up to him
Duplicated Bob and ran like a madman into the sunset
That’s her before she stole the motorcycle.
Pffft, Echo can fly at like… 200MPH at full speed! Did you see her in the Zero Hour short? She was flying like crazy, and with those awesome dodges!
On an unrelated note, I can’t wait to see what her Dance emote is like lmaooo
But why fly if you can majestically drive a motorcycle? 
She’s a high flyer, Will.
She belongs in the air.
Then impersonated the guy she stole it from, went to his home, kissed his wife, ate his dinner, told his kids bedtime stories then reverted back.
It got awkward, so she blew up the house with stick bombs and realized Winston still needed her. So she stole the tickets the family saved up for a holiday and boarded the flight and sat in economy class.
Taking the Bike with her 
Looks like a plausible story.
