Personally I'd prefer if it stays out of FreeBSD. All languages with package systems turn into a horrible quality over time. PHP Composer, Python Pip, node NPM and so on, initially it seems effective but the version dependency/issue hells are true nightmares. And I fear rust with cargo is going to be the same. Maybe I'm wrong, and in case it does go into base, I really hope I'm wrong so the quality of FreeBSD doesn't go down...