I would share things that are true now, but be careful about sharing things that may happen in the future. For future partnerships, the real risk isn't that your competitors find out. The real risk is that the partnership falls through and your employees feel demoralized. So I think it's fine and good to share information about the discussions your currently having with bigger companies, but less of a good idea to pr…
Demoralized is one thing, but also if enough partnerships are falling through they might get the sense that you’re not a good business person. Which may also be an accurate take away that you as a leader don’t want to hear/realize about yourself.
Without having been the leader of a startup I’d say the best thing to do is treat yourself like anyone else in the team ie the expectation of equal sharing back and forth. Help the team help you find out what your strengths are and what your weaknesses are.
Don’t try to hide your weaknesses or hope to get better at it. Especially if trying to hide/improve weaknesses are taking away from showcasing strengths. Instead get your team to hire in people to fill your weaknesses and learn from them. Meanwhile, double down on your strengths and continue the transparency and working as a team member.