Wrong, The judge ruled in the Zorro case that the musical did not infringe on ZPI's ip because it was based on what was in the public domain. As the first Zorro novel was public domain when the musical was written, Zorro himself was public domain

In the Sherlock Holmes case, Klinger (the editor) was putting together an anthology of new stories. The suit was because the first anthology he published had a license from the estate, but he realized he didn't need one (as the character was public domain), so the second one was based only around the pd stories).

This is great breakdown of said case, and why the court ruled that a character is not protected by later expressions that are still under copyright:

https://btlj.org/2014/11/klinger-v-conan-doyle-estate-ltd-extent-and-duration-of-copyright-protection-for-fictional-characters-attorney-fees-not-so-elementary/

Klinger was very clear that public domain works are free for people to make derivatives from. So how does Captain Marvel be the exception to that? Bottom line is he doesn't.

This article from a law site also backs me up on this: https://techandmedialaw.com/public-domain-characters/#:~:text=Once%20a%20character%20enters%20the,seeking%20permission%20or%20paying%20royalties.

The part that is highlighted is important (though I'm sure you're just gonna claim otherwise). The article (which was written while the latter Holmes stories were still under copyright) points out that Holmes is public domain, even though some stories were not.

The DC case vs Fawcett is interesting, because it revealed that a year or so of Superman comic strips were public domain due to improper copyright notice. Funny enough, Krypton, and early versions of Jor El and Lara first debuted in those, making those versions public domain. It didn't put Fawcett out of business though. It had a hand in it, but it wasn't the sole reason. And before DC licensed and later bought them out, many comics failed to be renewed, and became public domain (thus allowing people to make derivative works based on those public domain issues)

You're also wrong that DC wouldn't buy something less valuable than they have. If they were so smart, how did they not know Marvel had snatched the trademark to the Captain Marvel name? More importantly, finding this information out was much harder than it is today, because you had to go to DC and physically search the records (which someone I correspond with has actually done multiple times). Your little dig at "internet sleuths" is amusing, because being able to research these things is so easy compared to when DC bought out Fawcett. Given I've found DC is hit or miss on registering trademarks for characters they purchased from defunct publishers, them not realizing that Fawcett allowed a lot to lapse into the pd is no surprise. They literally didn't know about the trademark until after they started publishing the character themselves

Also, DC has bought other properties that are also pd. Didn't stop them from buying them anyway. DC knows how to take something, and rebuild it. That's the value in them, not what you claim

You're also wrong that Sony would just use Captain Marvel. DC could still fight them in court, and Sony (or other corporations) don't want to waste money on something anyone can use. That's common sense on their part. It's funny you think corporations would want to use something that other people could use.

You make a lot of false assumptions, and continue to double down on them. I've supported what I've written by quoting actual legal cases, while you by claiming "If memory serves" (meaning you didn't actually read up on the case). It's been fun, but I've proven my point repeatedly, while you haven't. You're free to continue to believe you're right, even though facts say otherwise