Not just hype.
Guardians as a product is way more popular than Ratatouille.
Sure, folks are always interested in a new ride, no matter what the theme. So for that reason alone there was interest in Remy.
But here you have on top of a new ride an incredibly popular product with a Marvel product.
Much like you had Star Wars product over at HS when GE opened and people flocked to see it because it was Star Wars. There what it included was 2nd to it being Star Wars. People were going period. And no, Marvel isn't quite as big a fan base as Star Wars but it's not far behind. Ratatouille has really no fan base at all.
Nor can I recall a single commercial, before OR after Remy opened, regarding the ride. I've already seen several (and I rarely watch commercial TV) for Guardians. Saw one this morning. If an AP holder hadn't gotten the email or otherwise seen an announcement, they'll have had a chance to see a commercial. More ways to know it's coming.
Even if it has as many openings as Remy had, I think it will go faster.