I’m sympathetic to your idea of calling it OSS or Open Software. But Richard Stallman and people who agree with his arguments really stress the “freedom” of what they call free software. They lost that battle ages ago, but they aren’t going to give it up since it’s more than just pedantry, it’s a value statement.
The problem with immortality is the damaging century long conservatism of society it would cause. Imagine a few rich immortals in charge of everything forever. Some scientists joke that “science progresses one funeral at a time”. Well imagine a society where the arts, sciences and the economy never change.