Is there a reason for java.time.ZoneId not including an Enum of ZoneIds?

To get a ZoneId it goes like:

ZoneId.of("America/Sao_Paulo");

or

ZoneId.of(ZoneId.SHORT_IDS.get("BET"));

Why would be the reason for not existing an Enum of such values, like:

ZoneId.of(ZoneIds.AMERICA_SAO_PAULO);

which seems less error-prone and a lot more auto-complete friendly?