I'd love to know where these ideas come from. All the way from the top? Product? Developers with a 20% time window? They've always been innovative and despite size/growth/scale seem to be able to keep that up.
We like to call it 100% time. Work on what you're interested in.
In this case, Ben — who handles a lot of our outreach to government agencies — knew that GeoJSON is something that could be a big deal for open data in government, so he built the feature. There's not much more to it than that.