ts-loader was started by James Brantly back in January 2015. He created the initial codebase, wrote the comparison testpack and merrily maintained it until it reached v0.8.2.
At that point John Reilly started maintaining ts-loader. On October 16th 2016 to be exact. The full story of how that came to be can be read here: https://blog.johnnyreilly.com/2016/11/but-you-cant-die-i-love-you-ts-loader.html
Since that time, John (who wrote this and finds it peculiar to refer to himself in the third person) has continued maintaining ts-loader. He appreciates any and all people that contribute. Who knows, maybe one day the mantle will be passed on again and someone else will step up and take ts-loader forwards. Who knows? It could be you ;-)