Well that's a strange thing,I also promoted to Div II,this season,and did not notice any drop in my fans so far .
I have won just 3 games,mainly because training my players is more important to me then winning games.
Just want to stay in 2 ,and thats no problem for me,and next seaon Iam gonna do a lot better,I hope.:)
I did a large expanding (almost 3000) on my arena,and it's not sold out ,but my fans still support me ,pretty good.
I fear the all star break a bit though,but Iam still in the Cup,and maybe that's the reason my fans keep coming to my arena.