What money have you paid to Universal yet, since you just booked a week ago?
We thought we were going to Universal for WW, but realized quickly once we got there that we were soooo wrong. We like the whole place. But you don't know that about you yet. If it's truly the only reason, and if you aren't going to be able to go back, then why go now?
On the other hand, it's one ride. DH has never ridden it because he doesn't fit. DS didn't go until our third trip there. It's totally possible to enjoy the heck out of Wizarding World without riding FJ. Heck, DH can't ride Dragon Challenge or Gringott's either. (and can't ride Hippogriff out at Universal Hollywood b/c the restraints are different) He still enjoys it.
Disney does NOT always announce things months ahead of time.
I take it you booked a package? It's fabulous to book room-only and then get tickets when you're ready. Way easier to change dates or cancel that way. Since I won't book a package (they are very rarely a better deal, they don't give you anything you can't get room-only unless it's for a very special event like a Wizarding World park opening or the Celebration of Harry Potter packages but those are generally more expensive) I don't know how much the insurance is, but you could likely find trip insurance at a better deal elsewhere.