We are booked on the same cruise out of Boston. I've been comparing the case levels to the previous Omicron surge. The USA recently passed 100,000 positive cases in one day (NYT). On the previous Omicron surge, the USA passed 100,000 positive cases around December 2. Three months later on March 3, the peak (Jan 14) had passed and cases were dropping (around 50,000 per day). With a 31 August sail date, we are more than 3 months away. Who knows what will happen, but if the surge in cases is similar to previous surges, then 3 months should be past the peak and heading towards a 'valley' in cases. I'd be more worried if the cruise was next week or next month. 3 months, I'm hoping cases to have gone down by then. But Variants will vary; that's sort of their thing.
There is no way to really predict, but our last cruise we lucked into going mid-March and that was a low transmission time. The months leading to it were quite scary however.
I will also be making final payment in the next few days if my TA ever calls me back.