Is the workplace the best place to discuss societal and political issues? No.
Should societal and political discussions be banned from the workplace? Also, no.
The problem with a ban is that it rarely hits where it aims. You might want to curb animated discussions on your internal tools and you end up making your people feel less comfortable expressing themselves.
We do live in challenging times. Most issues are polarized. Most fail to see the greys. Most feel the only possibility is to be fully in or fully out. And if your people want to talk about a delicate issue, your role as a leader is not to direct the conversation towards the appropriate forums, but rather to sit down with them and provide a safe forum for the discussion to happen.
Even if that means a loss in productivity.