'Bubble gum is available in many colors and flavors. A "bubblegum flavor" is the taste of the unflavored gum, made from chemicals such as ethyl methylphenylglycidate, isoamyl acetate, fruit extracts and others, although the exact ingredients were kept a mystery to customers.2 When blended, the chemicals and extracts fuse to make a sweet, palatable flavor. Gums made with vanilla, coconut, peppermint and almond extracts are available.'
Then goes on to list a range of specific flavours it is available in. While gum and bubble gum are available in many flavors, they also have taste of their own, which may be indistinguishable to many, and differ between brand, which perhaps makes "bubble gum" flavor a needless duplication of "Plain unflavored" above.
Sorry, but Wikipedia is simply wrong on that point. You can request fluoride treatments and children's medicine in "bubble gum flavor". But, no, that isn't simulating the flavor of unflavored bubble gum. It is simulating the default flavor of (many) bubble gum(s).
The default flavor of bubble gum is very sweet and quite strong and clearly fades as you chew the gum. You can taste unflavored bubble gum via "ABC gum" (already been chewed). It is not sweet, tastes nothing like "bubble gum" flavor, and can even be a bit unpleasant (varies by brand, IME).
And you would notice that flavor if you simply added "strawberry flavor" on top of it. Strawberry bubble gum does not have (much) of the default flavor added to it (depending on brand, it can have a note of (parts of) the default flavor so it tastes like strawberry with a hint of "it is still bubble gum" flavor).
Sources agree that the original "bubble gum" (both the style of gum and the flavor) was Double Bubble. One source sums up the original flavor source nicely:
The original flavor of Double Bubble is a closely guarded secret and no one knows for sure of what it is composed. All we know is that it is a mixture of fruity flavors derived from both natural and artificial sources. Later, other bubble gum companies copied the flavor as best they could.
Wrong again, bubble gum is a type of gum (available in many flavors). Different from chewing gum. The poll asks about chewing gum not bubble gum. Bubble is not a flavor. If you get this, or the reference you post why 'contribute' at all?