Indeed quite probably they have not decided yet.
Waffling/Rambling...
I know that is/has been the policy to try to find patterns/rules where none have been formally published by the authority for a timezone. Every/most years this causes airlines a hiccup for Tonga/Fiji.
e.g.
Actual flight time Auckland to Tonga is 2hrs 50mins. Up to November
5th, it is displayed as 2hrs 50mins. But from November 5th this is
calculated/displayed as just 1hr 50mins using IANA TZ info.
IATA who publish their own timezone updates to all IATA airlines based on authoritative communication from the governments concerned. IATA publishes that information as soon as announced, but IANA has
not/does not until near the effective date unless some more important change
forces a release.
e.g. Fiji have changed when DST ends in 2018
and that has been published by IATA so all airline schedules are now based on that change, but no TZ DB is offically available yet.
(
Have picked up your patch for that and used it to patch both JRE and JodaTime and that will go live next week hopefully for us
).
Anyway, have emailed
gov.to & tweeted to see if I can get an official position, but not too hopeful as, they just probably have not decided yet.