If currently a package is viewed in p.g.o you can see, which license is used. But this seems to be always only the value from the newest package, if it's masked. It would be nice, if it would be show either per version the license of at least from all version, since it's quite possible, that no every version of a package is always the same. Example: https://packages.gentoo.org/packages/media-sound/teamspeak-client Masked version has a different license definied than current stable, but only license from masked version is being shown.
This might be another example of something that should be in metadata rather than in ebuilds? Much more thought into implementation needed, of course. Just a thought.
I think, at least for some workaround, it would be nice, if just all licenses would be shown from all ebuilds?