Interesting thread! Ruger trademarked the names Security-380, Security-40, and Security-45, but by mid-2020, all were marked as abandoned at the trademark web site listed in post #1 (see page 2):
trademarks.justia.com
Ruger apparently had to reapply for a trade mark on the Security-380 name in February of 2022 (see page 3), to prepare for the production & marketing of that pistol. The company no longer chambers anything for the .40 S&W, so abandoning the Security-40 trademark is no surprise (albeit disappointing). And obviously, a compact Security-45 might have been interesting! Guess they can always reapply for those trademarks (as they did with the Security-380) if they change their minds!
As always IMHO, FWIW, YMMV, etc., etc.