Shouldn't MSDS data on products be publicly disclosed?
There is a bit of a misconception here.

Of course, the material safety data sheet (MSDS) is publicly available. Just go to your favourite chemicals supplier, type in your substance and download the corresponding MSDS in your language for your jurisdiction. At least in Europe that is mandatory for all chemicals a company sells; I would be very surprised if there is any developped country where making MSDS publicly available be not mandatory.

On the other hand there is the question of how a value was determined. That is not necessarily public information. Of course, there is a set of standardised tests that companies would perform, but they don’t have to exactly mention whether they used method A or method G. They also have a reason to be nondisclosive about this: imagine an animal rights activist calling you pretending to just be an interested scientist and then using the information they get on the phone to start a name-ruining anti-ChemicalCompany campaign. You don’t want that, do you? And then, of course, there is the general secrecy issue. If you just invented a compound you want to put on the market as a drug, you don’t want anybody knowing anything about it until you’ve started selling it.

Of course, government bodies have a certain reason to know how the tests were perfomed and what the raw results were (otherwise the company could just print a number on their MSDS which the responsible person invented on the toilet). But you’re not government. You’ll have to somewhat trust the government to properly monitor the companies in question.

Of course, the chemist who works safely doesn’t need to know how dangerous something is. They will work with it in a way that they are not affected.