Why is this not strictly a freedom of speech issue?

You have to look to the animal rights issue to find a good push-back to the corporate rights discussion, and to the rights of individuals with diminished capacity.

Humans who are very young and adult humans of diminished capacity may have someone speak for them. Their personhood is not in question, but the right to speak for them comes into play. Who will speak, and are they keeping the best interests of those individuals in mind? You may have seen the woman who thought she could interpret grunts for a brain dead husband years ago, and it was determined that she was simply speaking for herself and her understanding was made up. (This is an old story, it may have been on 60 Minutes long before the Internet). That kind of thing is at question when one speaks for another, are they serving the other individuals or themselves?

In the environmental movement there is a book that came out years ago called Do Trees Have Standing? that fed into the animal rights discussion. When people stand up to speak for non-human persons, or to demand personhood for non-humans, their motivation is in question and the rights they ask to support or fight for are highly subjective.

Corporations with personhood are a different creature. They have that personhood to protect the corporation's individuals from personal loss if the corporation takes a financial or legal hit. The corporation assets may be siezed, but the personal property of the corporation partners is exempt from seizure (though the individual corporate leaders can and do go to prison. This wasn't always the case). This corporate citizen is a sort of super-human personhood.

Free speech rights are what are being examined by the supreme court, in relation to the corporation as a person. But the corporation is usually standing for many actual humans who aren't necessarily of one mind, and if there are investors such as mutual funds, then the money of those individuals may be used in ways that those individuals oppose, in their name.

Newspapers and book publishers (after the 1960 decision around Lady Chatterley's Lover that prohibited the U.S. Post Office from blocking the distribution of print material it found objectionable) are one form of corporation that have free-speech rights from the Bill of Rights. The first ammendment oversees the speech of writers within the publishing corporation as well as the corporation itself.

A PR department of a non-journalistic corporation department is not the same as a publishing corporation, and I think the question will boil down to who is speaking for whom, and who is entitled to speak. The PR speech is sponsored to promote the needs and wishes of the corporation, it is sales speech, not freedom of expression. The sales speech can be examined and punished if it misrepresents an item. The owners of the corporation take a financial hit if there is an action against the corporation. The owners of a business corporation are invested in the production of something, and may not want it to engage in political speech on their behalf. A newspaper can spout off all it wants, be as hateful as can be, but that is free speech and is what those investors expect.

SRS