I had emailed the Wrigley's company a couple of weeks ago to ask them, and was told that all of the Extra gums were vegan, except the ones with the ice crystals, like the Extra Polar Ice, and with the hard coating. Here's what they wrote:
Thank you for contacting us about animal ingredients and our products.
To answer to your question, the vast majority of Wrigley products sold
in the U.S. are free from ingredients of animal origin, including egg
and dairy products. At present, the only chewing gum exceptions are
Extra® Polar Ice stick gum and Juicy Fruit® pellet gums.
Extra® Polar Ice gum and Orbit® Crystal Mint contain tiny flavor beads
encased in a microscopic layer of gelatin, which is animal based. We
have requested the development of a gelatin-free flavor bead that is
currently being worked on by our supplier. Juicy Fruit Grapermelon and
Strappleberry gums use shellac as a coating agent.