First of all, you’d have to filter out basic terms. There are several studies that show which words have higher frequency in everyday English use.
But! If you could gather this data, you could apply some cool machine learning applications to it. There are several simple ML algorithms used in processing English, to gather insights from data. We could easily do things like sentiment analysis, or text classification, given some data stream. Potentially these applications could be used to (hopefully) increase the player base.
To be clear - I’m not saying devs should have to volunteer to do this stuff or anything - I know everyone is busy.
I think for most used word usually way too common things such as "the" or "a" which are integral part of the language are dismissed. I'd say it would be best to look at most common verb/noun/adjective instead as those would give more meaning.