It's not a new rule - I found it in the 2012-13 rules. A warning is issued to fielders for certain types of obstruction and that is one of them. If that same fielder commits the same type of OBS again, a base is awarded. Here is the current rule.
188.8.131.52 A fielder shall not at any time obstruct a runner rounding a base.
184.108.40.206 A fielder shall not at any time obstruct a runner returning to a base.
220.127.116.11 A fielder shall not use force to push a runner off the base she possesses in order to put her out. (See Rule 18.104.22.168 if excessive force is used.)
22.214.171.124 A fielder shall not position herself in the base runner’s line of vision to obviously distract her or intentionally prohibit her from seeing the release of the pitch.
EFFECT—(126.96.36.199 to 188.8.131.52)—Delayed dead ball is signaled. The umpire shall issue a warning to the offending individual and notify her coach. Subsequent violation of the same rule by the same individual shall result in a one-base award to the obstructed base runner and each other base runner forced to advance. The awards shall be to the base beyond the base where obstruction occurred unless the base runner safely advances farther on her own, in which case no award is given.