The Spark website says 'Spark Sport will be live in time for the first F1® race, the FORMULA 1 ROLEX AUSTRALIAN GRAND PRIX 2019'.
I'd have though it's fair to:
1. take that statement at face value, and
2. assume it will work as intended. Given we're pretty close to F1 starting I think it's also to fair to assume that if the closed testing had thrown up any major issues Spark would have flagged a delay by now.
Am I missing something that suggests I should be more pessimistic?