Musk didn’t provide a timeline for availability, and you might not want to get your hopes up when it took years for Tesla just to post any source code. And this isn’t strictly a selfless gesture. If rival brands adopt Tesla’s approach, it could set an unofficial standard for connected car security that would look good from a marketing standpoint.
The code could provide a boost to connected car security if and when it arrives. There are few common frameworks (technical or legal) for safeguarding networked vehicles, and security might not always be a top priority. This could give companies a baseline level of security that would save brands the trouble of developing an effective defense from scratch.