I tried to see what a useTracker hook might look like, and it seems the following code is pretty close (including a drop-in reimplementation of react-meteor-data’s withTracker HOC on top of it)
import React, { memo, useState, useEffect, useCallback } from 'react';
import { Tracker } from 'meteor/tracker';
export function useTracker(reactiveFn, dependencies) {
const [trackerData, setTrackerData] = useState(null);
const callback = useCallback(reactiveFn, dependencies);
useEffect(() => {
let computation;
Tracker.nonreactive(() => {
computation = Tracker.autorun(() => setTrackerData(callback()));
});
return () => computation.stop();
}, [callback]);
return trackerData;
}
export const withTracker = options => Component => {
const expandedOptions = typeof options === 'function' ? { getMeteorData: options } : options;
const { getMeteorData, pure = true } = expandedOptions;
function WithTracker(props) {
const data = useTracker(() => getMeteorData(props) || {}, [props]);
return data ? <Component {...{ ...props, ...data }} /> : null;
}
return pure ? memo(WithTracker) : WithTracker;
};
Again, this would deserve actual real-world batte-testing, but it seems to be working fairly well – and the code is way simpler to grok than the current react-meteor-data 
example usage :
function MyComponent({ docId }) {
const doc = useTracker(() => Documents.findOne(docId), [docId]);
return doc ? <div><h1>{doc.title}</h1>{doc.body}</div> : <Spinner/>
}
