He could probably add marginal value in the near-term over Woods-Richardson. However, when Zebby Matthews returns, SWR will be headed back to the minor leagues. Now you have Civale on the team, so they'll be forced to either cut their brand-new acquisition or send Festa down to the minors. In that situation you have a veteran re-tread blocking a more talented minor leaguer who might actually be part of the team's future. I've read thousands of words on Twins Daily from people who are really tired of seeing below average veterans block rookies from getting playing time.
They don't desperately need Civale right now, they'll probably need him even less later. If they happen to need a 5th starter in the future it shouldn't be that hard to find some other veteran off a bad team's roster.