This is my understanding as well. I get great info talking with smallcap to the just barely midcap companies if you ask the right questions. Heck, usually, I am able to get a conference with a VP or CEO if my questions go above paygrade. I am no whale.

In practice, you will not get the same level of info on larger companies if you are not institutional or in a group of retail investors holding a decent share-count. Information obtained is usually a small amount above what is found on the conference call or via google.

As mentioned by the other comment, board members get preferential information sharing. I would haphazard to guess that Tencent balked at the purchase price of a seat on the board of directors (eg: 20% stake or something to that effect) or Tesla opposed it on principle. Probably the latter and then Tencent moderated their stake offer.

However, shareholders are afforded access regular updates on the financials of the company, which Tencent may be satisfied with on its own.

not if they have board seats

Is that true? I've never read the SEC rules or looked into this in detail but my understanding was that information sharing only becomes a problem if you actually trade on that information (ie. insider trading). I didn't know the rules actually tried to limit what was shared. How does that work with employees etc, who will almost certainly have access to a lot of preferential information and many also be investors or significant shareholders? Would love to know more!