I can verify this rumour.There are many ways to calculate the size of a vessel: Allure is 0,5 meters longer than Oasis and they have the other sizes, tonnage etc equal, so Allure is 'larger' then Oasis.
If I were in charge of a cruise line, I would bring back the classic ocean liner design. Something like the Queen Elizabeth II or the original Oriana. Not these city blocks.