You need to be specific about the circumstances. But you need to understand that a patent is nothing more than a registration (it is not built in protection), and releasing details sooner than needed could attract Chinese assholes who copy everything with no regard for anything.

Maybe they used a controversial technology such as stem cells, or controversial research techniques such as animal testing during the development of the invention and product. Anonymity helps protect them from those who sometimes violently oppose such technologies and techniques. In the UK mention of the inventor is covered by the Patents Rules 2007 (as amended, Rule 11 sets out how an inventor can apply to have his or her name or address kept unpublished.

The vast majority of patent applications are published 18 months after their filing date, releasing the inventors' names (and municipalities) to the public.

I can't see any real advantage in keeping their names secret unless they want to delay being sued for misappropriation of trade secrets of former employers or something else for which they're trying to delay notoriety.

I wouldn't release any info I dont have to. Why does that matter to you?

In a case where a patent for a product is still pending, why do you think the person or team who invented or formulated the product would not want their name released until the product is fully patented? The product is already being sold to thousands of people and seems to be very successful in a short amount of time.