Right, I had that same exp for it as well. I'm just curious to know what it may have been after Club N implemented the 120 day exp on Post-Play surveys, and if the 120 day range would have extended it past the 4-year release anniversary. Here's a list of 2009/2010 games that could provide info had they been registered around the Apr. 7 PP survey cutoff date:
Released 2009 (Apr-Aug):

Rhythm Heaven....................................................4/5/2009

Personal Trainer: Walking....................................5/25/2009

The Legendary Starfy...........................................6/8/2009

Excitebots: Trick Racing.......................................4/20/2009

Punch-Out!!..........................................................5/18/2009

New Play Control! Donkey Kong Jungle Beat......5/4/2009

Wii Sports Resort.................................................7/26/2009
Released 2010 (Apr-Aug):

Picross 3D..............................................................5/3/2010

Dragon Quest IX: Sentinels of the Starry Skies.....7/11/2010

Super Mario Galaxy 2............................................5/23/2010

Sin & Punishment: Star Successor........................6/27/2010
So, for the above 2010 games, except S&P, I registered all of them pre 120-day PP exp. What's weird is that DQ IX had a 2014 PP exp, while the other two still have 2015 exp dates!!! WTF?!?!
I'm starting to think that PIN inserts with printed registration exp date gave 4-years. I can confirm that Picross 3D does NOT have an insert exp date and that S&P does, but cannot confirm for SMG 2 (can't find it). So... it seems somewhere around late May to June 2010 when they started printing the exp dates on them is when 5-year Post Play exp went to 4-years, therefore the same exp date as the registration exp date.
If that is all true, the two games for which I did not receive PP surveys should have been extended like S&P was (which I registered at the same time). So DQ IX should have acted like S&P and also have been extended. Of course, none of this matters now... :lol: