They didn’t lock old.reddit out of new features; it’s a really unwieldy codebase, and making changes to old,reddit is like shaking a wooden water tower. It holds up the water tank as long as it’s a static load, not dynamic. I’ve had to read / maintain / debug source code in my career - and I’ve read the old open sourced Reddit code, and it is … well, it’s not designed for building up and out. It’s not even designed for maintaining over time. It was designed to get a message board running with occasional weekly downtimes, and a lot of “you broke reddit” and a bunch of RSS feeds and API endpoints, and no view to end user experience. It was built with the same mindset as building windows 3.1. Coding some of the features would be like backporting their support code to windows 3.1 - but not as libraries, as device drivers.