My sense, personally, is that mostly that people have the causality on legal formalism reversed: originalism is not a theory that leads to conclusions, it's a rationalization used to support conclusions already held.
But at the very least what you're saying is something worth thinking about. Given that Oyez makes every supreme court oral argument public and the filings are clearly public, it seems like there probably would be a case for any number of text learning methods to try to identify formalist style in legal arguments for an analysis like this.