That is not what is on the Oceania website, perhaps it's all a moving target, perhaps each line has different guidelines, but right now what is on the Oceania website says this; also see this link as to what is currently on the Oceania website, notice the date; (of course that "SUBJECT TO UPDATES" is the key to all of it)
sail-safe-program.pdf (oceaniacruises.com)
FOR SAILINGS EMBARKING ON OR AFTER AUGUST 1, 2022, Oceania Cruises will no longer require guests to produce a negative covid test to embark their cruise, subject to local regulations.
Please Note: Voyages embarking from Canada and Greece as well as those sailing to Bermuda, will still require a negative covid test at embarkation, until further notice