When a token is exiled from the battlefield, it does change zones — it moves from the battlefield to the exile zone. This zone change is enough to trigger any ability that says 'when this creature leaves the battlefield' (CR 603.6). The trigger fires as the token moves to exile.
Tokens do have a special rule: they cease to exist as a state-based action when they are in any zone other than the battlefield (CR 111.7). However, this happens after the token has already arrived in exile and after triggered abilities have had a chance to trigger. The token ceasing to exist does not retroactively prevent the trigger from existing on the stack.
It's important to note that because the token ceases to exist in exile, abilities that try to do something to the token in exile (like returning it from exile) will fail to find it. But the trigger itself still goes on the stack and resolves normally.
Example: You control a creature with the ability 'When this creature leaves the battlefield, draw a card.' An opponent exiles it with a spell. The token moves to exile, triggering the ability. Even though the token immediately ceases to exist in exile (CR 111.7), the triggered ability is already on the stack and you will draw a card when it resolves.
Key rules: CR 111.7 (tokens leaving the battlefield cease to exist), CR 603.6 (when triggered abilities trigger from zone changes), and CR 700.4 (a 'leaves the battlefield' event is a change from battlefield to any other zone).
Unofficial fan resource — not affiliated with or endorsed by Wizards of the Coast. Answers are AI-generated estimates grounded in the Comprehensive Rules and are not a substitute for an official judge. Verify anything match-critical.