No it changed for the Pride (at least - maybe more cruises??)
What was (or maybe still is) on the their webpage - no booster required just strongly recommended. Now the bottom part (of this post) for Pride cruises - a booster IS required.
VACCINATION REQUIREMENTS (from the web page)
Vaccinated cruises are available for guests who have received their final dose of an approved COVID-19 vaccine at least 14 days prior to the sailing day (not counting embarkation day) and have proof of vaccination.
Additionally, the CDC has strongly recommended that individuals obtain a COVID-19 booster vaccination, when eligible. Should the CDC definition of fully vaccinated evolve to require the booster shot, our policy will adapt accordingly.
For this cruise - Pride - From today's email
Additionally, all guests 12 years and older who are fully vaccinated and are more than 6 months months past the date of the last dose of their initial vaccine series, will need to show proof of having received a booster in order to sail. This means getting an mRNA booster dose (Pfizer or Moderna) before entry into Europe and no later than 6 months from the last dose in your primary series.