fact vs. opinion

I would say the statement itself is a fact, not an opinion. It is expressing the fact that everyone expressed the same opinion (or preference).

Opinions are often stated as facts; of course statements are often just the opinion of the writer, unless quoted or otherwise.
In an academic treatise one must ask where is the evidence; was there as survey of "everyone" in this case or is the statement just wishful thinking on the part of the writer?
Sometimes journalists say or write things like "everyone here is (something or other)"; and one must wonder how many people they asked and whether the respondents reflect a proper (random) cross-section of "everyone".

There is a tradition in English academic (and business) writing to avoid the first person and not to preface every sentence with "I think that". One of the results is that opinions tend to be stated as if they are facts.

The above is of course just my own opinion. You should wonder where the evidence is.

I would say that it depends who is making the statement and what position they are in to know about how "Everyone..." was feeling.

If the person offering that "Everyone wanted to..." can speak for everyone else because they have already gained knowledge of what everyone else wanted, then it is might possibly be a fact. Of course then you could question the validity of that person's knowledge. Did they gain it by observing everyone else's demeanour (so they might not be totally sure)? Or did everyone else volunteer this information?

Alternatively, it could be pure conjecture. The person speaking felt that the new ride looked exciting. They wanted to persuade someone to go on it. Therefore saying "Everyone wanted to..." might be a useful way to persuade the other person.

I should state that I tend to be sceptical about things that look like "facts" but I'm ok with that. I don't mind people having subjective opinions either. I just like to acknowledge them as such.