Hi Lex! Thanks for the participation.
Babel transformations often mimic ECMA specifications, but they aren’t required to be standards. For example, React’s JSX is transformed despite not being an ECMA standard. Whether or not lazy-loaded modules becomes a standard, the Babel plugin will always be able to transform it from non-standard syntax to standardized ES5. If a standard changes, you can leave the existing Babel plugin, or you can update your code to match the standard.
Fetch already has very strong browser support with a great polyfill alternative. You only need to use the polyfill if a significant amount of your target audience lies in that 8% unsupported browser range, primarily Internet Explorer.
While I haven’t contributed to React itself, I try to be active in the React community in general. I’ve helped a little with Material UI, but primarily address users directly through Reddit’s /r/reactjs/ and /r/learnreactjs, various Slack and Discord channels, and my own open source publications. Joining the React team would be a great opportunity for me, but I am currently maximizing my growth potential at AWS (I should include that opinions stated are my own and do not reflect those of Amazon or its subsidiaries).