You should be fine but nothing is guaranteed and it is Intamin.
Having said that, it sounds like ride testing is now in full swing and the coaster part is probably the thing most likely to go wrong. For Universal to make the announcement with an opening day, early tests must be promising and performing like they want.
The final AAs are getting installed and then it's more testing and landscaping.
Overall, things are looking good and Unviersal don't want a repeat of Gringotts. If I was to give a percentage? 99%+ chance it will be up and running for opening day.
Fighting the crowds though is all on you.