more Public Domain Hanna-Barbera works..?

So a friend on Discord told me that he saw no renewals for the episodes of The Yogi Bear SHow and the first episode of Lion and Hardy Har Har.

Now Lion Hardy Har Har has almost all of the episodes renewed, i checked:

https://publicrecords.copyright.gov/search?page_number=1&query=%22%20Lippy%20Lion%20and%20Hardy%20Har%20Har%22&field_type=%22keyword%22&records_per_page=100&sort_field=%22copyright_number_for_display%22&sort_order=%22asc%22&registration_class=%22RE%22&model=%22%22 HHowever a friend told me here that there is no renewal for the first episode "See-Saw"

Yogi Bear's first appearance was renewed according to Wikimedia, however i seen no renewals for the 1961 The Yogi Bear Show: https://publicrecords.copyright.gov/search?page_number=1&query=%22yogi%20bear%20show%22&field_type=%22keyword%22&records_per_page=10&sort_order=%22asc%22&registration_class=%22RE%22&model=%22%22 (Cindy Bear's first appearance and i think other Characters?)

I mean i thought Hanna was good at keeping copyrights to their old stuff, but maybe i was wrong..? But seeing how six episodes of the 1958 Felix cartoon slipping into the public domain due to sloppy registration and renewal. But THE YOGI BEAR SHOW is free?! Idk why Hanna-Barbera didn't renew that show as it was popular, but that's a big loss for the studio there.

Now i could be VERY wrong, so take this with a grain of salt. But i did indeed see no renewals for the episode.

As a Hanna-Barbera fan i am kinda surprised.