It's mindblowing nobody thought about this simple solution before. As there are fans of both versions, there should be two types of ranked 4vs4 Feast: with free chat and simplified pvp-macro chat (current type).

4vs4 muted will naturally become a learning ground for low tier matches (in my experience most of newbies don't want to hear any advice anyway because they think they do nothing wrong), and free chat version will be for players who want to communicate and for high tier matches where custom macros, markings and other stuff are more important.

4vs4 light party should be with free chat because there's no reason to be muted. It's not like a team of 4 friends will go there and start insulting and reporting each other. That's, like, makes no sense to keep it as it is now.

8vs8 is a complete mess and with chat or muted will not affect anything, people didn't read the chat when it was unmuted and were 10 stacking and suiciding since day one.
Two versons of it, however, will increase waiting time so just one is fine. Maybe it's better to keep it as first, novice version of pvp for people to run around and accustomize with their abilities before going in more serious ranked matches.