Was Millie a bilingual macaw or a bilingual parrot?

Dear Editor,
A historic magazine was published of Guyana’s participation at the EXPO 1967 in Canada and the ‘Forward’ was penned by one Frank Pilgrim, Public Relations Officer to the Prime Minister.
It was also the event where “Mille” became world famous for swearing in both the French and English languages respectively. I will also add that in commemoration, stamps were produced in four different colours in the denominations of five and 25 cents with “Millie’s” photo attached.
However, as a philatelist, avid reader and collector of historic artefacts, I stumbled on something on page 17 of the magazine mentioned above and I would like to agree with F Pilgrim’s description ‘Millie the macaw.’
The stamp which was produced described “Millie” as a bilingual ‘parrot.’
At first glance, I believe almost every human on earth will say or agree that “Millie” is a Macaw. However, if anyone was tasked to prepare a research paper, they will produce one saying that macaws are specie of the parrot family which is totally accurate.
Did Guyana get it wrong with the description of “Millie” as a bilingual parrot instead of a bilingual macaw?
Could it be considered an error on the stamps and perhaps should be included with other stamps globally in that category?
I am opened to be schooled by an English major, historian, specialist on the subject of parrots and macaws, general public…

Yours faithfully,
T Pemberton