...It's interesting that Warner Bros/DC/ATT didn't demand that all the Fawcett scans be removed, much less all the Captain Marvel related ones. Thanks for providing all those scans....
WarnerMedia has no legal claim to any material that wasn't legally transferred to them and renewed - Fawcett or Quality, for that matter - so they can't stop anyone from using them.
If you look at the start date of the renewals (except for the 6 WHIZ/CMA renewed in the 1960's) it lines up to the period DC/NPP got the license to publish Captain Marvel.
The "missing" handful of renewals post-early 1945 is simply due to missing paperwork from Fawcett's files that never got transferred over to DC! When they got the rights, including reprint rights, the bulk of the Captain Marvel/Marvel Family related titles (8 1/2 years worth) were still under the first copyright term.
Also, as I noted, you'll notice only Captain Marvel/Marvel Family related titles post-early 1945 were renewed - all other Fawcett comics WERE NOT! (Which explains why "Bulletman" issues #14-16 and "IBIS" 4-6 are PD for instance!)