I wouldn't worry about it at all. Even back when they started this poll in the mid 2000s, Ayu never placed very high at all. Her highest placement ever was like #16 or something in 2005. From what I can see in the rankings that I have found, Oricon Style subscribers are very set in what they like and what they do not like.
Past rankings -
2004 - cannot find/was only in the magazine, Utada Hikaru #1
2005 - #18, aiko #1
2006 - did not appear in the top 10, aiko #1
2007 - did not appear in the top 10, Utada Hikaru #1
2008 -
#25, Utada Hikaru #1
2009 -
#26, Mr. Children #1
2010 -
did not appear in the top 30, ARASHI #1
2011 -
did not appear in the top 30, ARASHI #1
2012 - #50, ARASHI #1
Oricon Style subscribers are just
not Ayu fans and never have been. Back when Utada was active, she was #1 on the poll a bunch of times. Or maybe that was aiko...