Air Ministry Orders in 1939 and then again in 1941 stopped the practice of including roles (e.g Flying Boat) in badges. In effect, there are two official badges - the current one, without a role included in the border and the old-style one.
Links with locations (74 [Trinidad]; 139 [Jamaica], etc, etc) were brought to an end in 1952.
There were several reasons for this - these included the fact that some squadrons had adopted these names for reasons which weren't entirely clear, and even the Air Ministry had been a bit too busy between 1939 and 1945 to see whether the link should be made official. Also, as it was appreciated that many squadron numberplates would disappear as the RAF reduced in size, there were concerns that disbanding a unit could cause problems, particularly if the unit had the name of a country in its title.
This didn't stop squadrons from continuing their links with other nations, though - when 139 disbanded, the Jamaican government demanded (as near as damn it) that the squadron be reformed instantly, since it was an insult to Jamaica. A polite 'don't tell us how to number our squadrons' missive was sent to the Jamaican govt, pointing out that no RAF squadrons had been known by their affiliation since 1952 (at least not officially, although they didn't say this), as the result of an AMO, and therefore, the FCO and their Airships regretted that 139 could not be granted special treatment - although there was a possibility (this was true) that it might appear as a Buccaneer squadron in due course.
By the by, II(AC) were at one point in breach of two AMOs - one which required all squadrons to use Arabic instead of Roman numerals, and another which said that a role, current or historic, shouldn't be stated in brackets after the number. II(AC) appear to have mislaid the instruction, and allowed the bureaucracy to come round to their way of thinking in due course...