Why not simply add LTS to the package description? The Linux61 kernel and modules →
The Linux61 LTS kernel and modules
With this, it’s easy for all users to find the LTS with all tools (pacman, pamac, …) and with a small change in (mhwh-kernel, manjaro-starter, packages.manjaro.org, …).
If new users were able to identify an LTS with pamac or pacman they may incorrectly assume it is ok to install kernels using these tools rather than Manjaro Settings Manager GUI or mhwd-kernel