The Autoware Foundation TSC meetings are only open to premium members of the foundation. The minutes are, as you know, open after the meeting is completed.
If you are interested in joining the foundation, I recommend you get in touch with us via the autoware.org website and we can provide you with information on the membership levels, ways to contribute, etc.
If you are just generally interested in Autoware and want to join the community, then joining the Slack chat is a great place to start.