That list is available Full Installers, not minor updates. So the Major Updates Deferral is in fact not applying to the minor updates, to see a list of available minor updates (that have not yet been installed use softwareupdate --list instead, these are the updates governed by Minor Updates Deferral.
All the --list-full-installers shows is that if you were to attempt to upgrade to macOS 13 or macOS 14 from macOS 12, the Major Upgrade Deferral would apply since the current minor versions of 13 & 14 on offer are still within the Major deferral period.
Here's a current view from mist (command line version, another utility that can list available full installers, it has a gui version as well:
mist list installer
┌──────────────────┐
│ INPUT VALIDATION │
└──────────────────┘
├─ Search only for latest (first) result will be 'false'...
├─ Include betas in search results will be 'false'...
├─ Only include compatible installers will be 'false'...
├─ Output type will be 'ascii'...
┌────────┐
│ SEARCH │
└────────┘
├─ Searching for macOS Installer versions...
└─ Found 29 macOS Installer(s) available for download
┌───────────────┬────────────────────┬─────────┬─────────┬──────────┬────────────┬────────────┐
│ IDENTIFIER │ NAME │ VERSION │ BUILD │ SIZE │ DATE │ COMPATIBLE │
├───────────────┼────────────────────┼─────────┼─────────┼──────────┼────────────┼────────────┤
│ 072-44286 │ macOS Sequoia │ 15.2 │ 24C101 │ 15.29 GB │ 2024-12-12 │ True │
│ 072-29965 │ macOS Sequoia │ 15.1.1 │ 24B2091 │ 12.73 GB │ 2024-11-20 │ False │
│ 072-30111 │ macOS Sequoia │ 15.1.1 │ 24B91 │ 14.56 GB │ 2024-11-20 │ True │
│ 072-12295 │ macOS Sequoia │ 15.1 │ 24B2083 │ 12.73 GB │ 2024-10-31 │ False │
│ 072-12353 │ macOS Sequoia │ 15.1 │ 24B83 │ 14.56 GB │ 2024-10-29 │ True │
│ 072-01382 │ macOS Sequoia │ 15.0.1 │ 24A348 │ 14.48 GB │ 2024-10-22 │ True │
│ 072-36705 │ macOS Sonoma │ 14.7.2 │ 23H311 │ 13.67 GB │ 2024-12-12 │ True │
│ 072-09041 │ macOS Sonoma │ 14.7.1 │ 23H222 │ 13.67 GB │ 2024-11-05 │ True │
│ 072-36728 │ macOS Ventura │ 13.7.2 │ 22H313 │ 12.22 GB │ 2024-12-12 │ True │
│ 072-09024 │ macOS Ventura │ 13.7.1 │ 22H221 │ 12.22 GB │ 2024-11-05 │ True │
│ 052-60131 │ macOS Monterey │ 12.7.4 │ 21H1123 │ 12.42 GB │ 2024-03-19 │ True │
│ 042-45246 │ macOS Big Sur │ 11.7.10 │ 20G1427 │ 12.42 GB │ 2023-09-12 │ False │
│ 001-68446 │ macOS Catalina │ 10.15.7 │ 19H15 │ 08.75 GB │ 2020-11-12 │ False │
│ 001-57224 │ macOS Catalina │ 10.15.7 │ 19H4 │ 08.75 GB │ 2020-10-28 │ False │
│ 001-51042 │ macOS Catalina │ 10.15.7 │ 19H2 │ 08.75 GB │ 2020-09-25 │ False │
│ 001-36801 │ macOS Catalina │ 10.15.6 │ 19G2021 │ 08.75 GB │ 2020-08-13 │ False │
│ 001-36735 │ macOS Catalina │ 10.15.6 │ 19G2006 │ 08.75 GB │ 2020-08-07 │ False │
│ 001-15219 │ macOS Catalina │ 10.15.5 │ 19F2200 │ 08.74 GB │ 2020-06-16 │ False │
│ 001-04366 │ macOS Catalina │ 10.15.4 │ 19E2269 │ 08.75 GB │ 2020-05-05 │ False │
│ 061-86291 │ macOS Catalina │ 10.15.3 │ 19D2064 │ 08.69 GB │ 2020-03-24 │ False │
│ 061-26589 │ macOS Mojave │ 10.14.6 │ 18G103 │ 06.52 GB │ 2019-10-15 │ False │
│ 061-26578 │ macOS Mojave │ 10.14.5 │ 18F2059 │ 06.52 GB │ 2019-10-15 │ False │
│ 041-88800 │ macOS Mojave │ 10.14.4 │ 18E2034 │ 06.53 GB │ 2019-10-24 │ False │
│ 041-91758 │ macOS High Sierra │ 10.13.6 │ 17G66 │ 05.71 GB │ 2019-10-20 │ False │
│ 10.12.6-16G29 │ macOS Sierra │ 10.12.6 │ 16G29 │ 05.01 GB │ 2017-07-15 │ False │
│ 10.11.6-15G31 │ OS X El Capitan │ 10.11.6 │ 15G31 │ 06.20 GB │ 2016-05-18 │ False │
│ 10.10.5-14F27 │ OS X Yosemite │ 10.10.5 │ 14F27 │ 05.72 GB │ 2015-08-05 │ False │
│ 10.8.5-12F45 │ OS X Mountain Lion │ 10.8.5 │ 12F45 │ 04.45 GB │ 2013-09-27 │ False │
│ 10.7.5-11G63 │ Mac OS X Lion │ 10.7.5 │ 11G63 │ 04.72 GB │ 2012-09-28 │ False │
└───────────────┴────────────────────┴─────────┴─────────┴──────────┴────────────┴────────────┘
What is important here is the Date column, it shows the date when each full installer was released. This can be confirmed at https://sofa.macadmins.io/. Apple also often removes older minor update full installers at around the 90 day mark to also provide a means of helping to manage deferrals, but this has the side effect of what we are seeing right now, where if going from macOS 12 Monterey, the only full installer available is for 15.0.1. So let's say you then upgrade to 15.0.1, the computer would then offer minor updates to 15.2 (assuming the Minor Updates Deferral has not been applied). It is a quirk of how Apples Major/Minor Update Deferrals are applied, but an important distinction.