And you're misunderstanding that quote. That line doesn't mean they had no expectation of sequels. Of course
they were hoping for sequels. They just weren't sure
whether it would succeed. They were taking a chance, and they were realistic enough to know there were no guarantees, but it's not like they would've given the franchise to Abrams if they didn't think there was a reasonable chance the film could spawn sequels. Your problem is that you're taking something that's in the middle ground -- the studio being realistically prepared for it going either way -- and interpreting it in all-or-nothing terms, assuming that just because they didn't assume
it would succeed, that meant they expected it to fail.