That's... not remotely true. A built JS bundle consists of least-common-denominator JS that in theory should continue to run ad infinitum. "Don't break the web"

That's... not remotely true. A built JS bundle consists of least-common-denominator JS that in theory should continue to run ad infinitum. "Don't break the web" is a mantra among browser devs. Rebuilding the bundle from scratch might be more complicated. But you don't need to do that to preserve it.