The solution for Meteor v3 and onwards can be found in How to NOT import React with 3.3.0? - react - Meteor Forum
Basically, just create the .swcrc file in root with the following content.
{
"jsc": {
"transform": {
"react": {
"runtime": "automatic"
}
}
}
}
Meteor already has the speedy web compiler integrated, so it should work just fine with that.