While waiting to see if this becomes an option, there is a way to get this info without players knowing. I have set up several macros for rolls and general info specific to the group I am running. Languages is one of the things I wanted to have access to... This is for the Pathfinder by Roll20 sheet, but it should give you an idea of what can be done. Just need to see how to access it on your sheet.
/w gm &{template:pc} {{showchar=[[0]]}} {{charname=}} {{name=Group Languages}} {{type=attackdamage}} {{roll=}} {{descflag=1}} {{desc=**S'werc Soloe**: @{S'wrec Soloe|languages}
**Lily**: @{Lily|languages}
**Dax**: @{Dax|languages}
**Sanos**: @{Sanos|languages}
**Salazarr**: @{Salazarr Antonio de Oliverira|languages}}}
Since I am wanting all characters at once, I reference them all by name instead of as selected or target.
Just thought I would post in case you could use a way to work around this limitation.