The steering would be ever-so-slightly "lighter" -- I don't think it would be perceptibly less stable. You could restore the original trail by going to a fork with 40mm of rake, but it would definitely not be worth it for so little a change. 650x38B tires (like the Soma B-line) would make up half of the difference and be better on gravel if you haven't already purchased the tires.

Here's my go-to trail calculator: http://www.yojimg.net/bike/web_tools/trailcalc.php