Presumably the Blu-ray discs in these 3-disc sets are the 2019 remasters?
They are indeed mate.
Australia also had a similar release to the UK (3-disc sets of the individual films; a 4K, a blu ray, and a bonus disc) earlier in the year.
That set also has the 2019 SE version on the blu ray disc - confirmed here by Nathan Butler on his youtube channel:-
https://www.youtube.com/watch?v=ulN76xipoaE - Nathan discusses the 3-disc Aus content around 4 minutes in.