> The author IMHO can relicense their code to whatever their like.
Assume it's true and consider what it can lead to. Person A writes code under GPL. Person B extends that code significantly, also under GPL. Person A relicenses his code to a closed source.
Now person B, of course, is the rightful owner of his own extensions, but they don't make sense without person A's code. So suddenly person B's work greatly decreases in value.
I'd assume it's not as simple as just relicensing one's own code; other contributions, depending on that, should be taken into account. Or you can't just relicense.
Assume it's true and consider what it can lead to. Person A writes code under GPL. Person B extends that code significantly, also under GPL. Person A relicenses his code to a closed source.
Now person B, of course, is the rightful owner of his own extensions, but they don't make sense without person A's code. So suddenly person B's work greatly decreases in value.
I'd assume it's not as simple as just relicensing one's own code; other contributions, depending on that, should be taken into account. Or you can't just relicense.