This should be at the top of their list of legislation that needs to pass while they have the opportunity and the numbers to make it happen. Otherwise, the House leadership won't be able to enforce any rules since this incident has made it clear there's no teeth in the existing rules.
Whether the threatening letter from Eric Holder and the Memphis law firm actually had an impact is a matter of speculation, but it could well be that the House leadership decided that getting into an extended legal battle would only serve to give the two anarchists more opportunity for publicity. Also, even if they had won the legal battle and kept them out of the House, the two districts - especially the one in Memphis - would've appointed/elected two replacements with exactly the same political values and attitudes as the "expelled two."
The TN Congress needs to change the rules and laws that support them so they won't be forced to tolerate similar disruptions in the future. Without order, chaos on the floor will become commonplace and they won't be able to pass any legislation that a few dissidents don't like.