I'm being told by a player that it was ruled at gencon that hindering in your starting area is ignore until you move out of it. Can I get where in the rule book this is at

It is not.

This was a rule for battle royals only, and it was for previous years. The reasoning is that in those games (prior to 2014), they didn't have official maps, so they cut down regular 2 player maps into squares, and starting areas were in the corners. This led to terrain disadvantages, so they ruled the terrain is ignored until you move out of it.

Thank you for your super quick response