There's an interesting and formally unresolved (because the applicable window for the earliest "copyleft" works hasn't yet arrived, for one thing) question about how this interacts with things like CC0, GPL, and more informal licenses to the public at large. The law requires the termination to fall into a specific 5-year window, with advance notice in writing (and it must be multiple years in advance), served specifically to the person whose rights are being terminated.
The sheer logistics of trying to terminate a license granted to the world are therefore pretty difficult, but you could imagine termination targeting just a handful of lucrative targets. (Even then, when does a generally-available license "start"? When it's first offered? When the specific user first accesses the work? Is the timeframe "refreshed" every day the license is still on offer? This provision really wasn't written with these kinds of licenses in mind.)
It's probably one of the more complex parts of copyright law. There's a few well-known cases of section 203 being used to claw back copyright decades down the line. (Note: I'm am very much not a lawyer)
In 1938, John Steinbeck granted Viking Press rights to publish 13 of his works, including Of Mice And Men, The Grapes of Wrath, and Tortilla Flats, as long as they were kept in print and for sale. In 2005, John Steinbeck's son and granddaughter served notice to Penguin Publishing, who were the interested party at the time, that they were terminating the agreement.^2
This section was originally designed to give artists who may have essentially (or even literally) given away their rights due to inequitable bargaining power a chance to recoup their property down the line with at least several years notice that they are planning on terminating the agreement.^3 In practice, however, it's kind of a mess, and to say that it would allow an artist or their heirs to terminate a grant to the public domain is dubious. It's something that would likely see its way to the supreme court should it ever come to pass.
I've included a couple other articles here just in the general interest of providing more info.^4^5
[1]: https://www.copyright.gov/docs/203.html
[2]: http://billgablelaw.com/sites/law/files/TakingItBack.pdf
[3]: https://abovethelaw.com/2019/05/terminators-mount-up-section...
[4]: https://media2.mofo.com/documents/190700-all-shook-up.pdf
