We've been to the CWS (albeit nearly 20 years ago.) We've been #1. We have stretches of winning conference championships, going to regionals, winning regionals, hosting both regionals and super regionals. We have a great new stadium that the play on the field has not matched.
Of course fans will have high expectations. Whether they are justified or not is of no consequence. Fans want to see their team perform at a high level and it's much more fun to simply "hope" that that will happen. Naturally, when you get a big dose of reality after watching a bunch of bad baseball some fans have to go through the 5 stages of grief before they reassess expectations.