Elephant ivory
It is a big planet and not everyone will read your post. All will not read mine either.
You can only control what you can. No telling what all countries and all people are doing.
It may be more likely ivory is being used for artistic carvings and ear rings than cue parts - but no way to know.
AZ is a global forum, but operates out of the U.S.A. I think the U.S.A. has implemented laws that minimize the likelihood that a well known cue maker with an established reputation would do anything other than use legal ivory. If illegal ivory was “free”, would a cue maker risk using it just to same some money on a single cue? None of this "legal ivory" used in the USA is likely to have had much of an effect elephants disappearing in the countries you listed - but that is my opinion.
It is possible that some ivory and hide come from an elephant that dies from old age or natural causes. There is not evidence to support that the tusk and hide are unusable unless from hunting down a living elephant and killing it.
The Countries you list could reverse this course if they choose to spend money to do so. It is partly their fault that Sumatra, Thailand, Sudan do establish hunting laws, enforce them and fund wildlife management. If one listed every fault contributing to elephant extinction I expect - if you can not exceed 100% in aggregate - that cue parts from elephant ivory would have to be a low percentage.
I have a cue with a mammoth sleeve and a piece of the ivory to prove to me it was mammoth ivory that I can analyze based on “Schreger lines”. No telling if this mammoth was the last one left and this ivory caused the extinction of mammoths. I do not worry about hitting balls with the cue.
See:
http://www.lab.fws.gov/ivory.php
Is it possible you would feel different about using a cue with Legal ivory and the paperwork to prove it? Only you can decide – but if one is unable to consider evidence in that decision, It is narrow minded to think that pre-ban ivory (before 1989 – if I understand this correctly) is still eliminating elephants . (Not meaning to imply you or anyone on this issue that supports one side or the other is narrow minded, just asking that you consider the realities of evidence and % effect that cue parts does have.)
I am willing to consider evidence - past, present and future.