You are right the e-Golf is popular - maybe not in the USA but I believe the sales in Norway, Germany, the UK and the Netherlands are pretty significant. VW sold 100,000 e-Golf as of November 2019, and I'm pretty sure they are still making them, so this bodes well for tinkerers to find an upgrade solution. It is possible someone will come up with a battery swap but I doubt it will be easy or cheap. The cells are a standard size and the while the "big" pack has 37 Ah cells, 50 Ah cells have been common for years. Maybe we can expect 60 to 70 Ah cells in the future?
2017 e-Golf LE, Multi Coat White with Black Vegan Leather interior