I am not a MyHeritage member, so cannot help there, but you are right that further work is needed as relying on family tree sites where users can post trees sometimes based on little evidence, which others cannot label as demonstrably untrue, is always a risk.
I had a look in Ancestry (all the above disclaimers apply!) - I found a few member trees with Geraldine LEACH m to John Hussey Burgh MACARTNEY, dying in 2005 Sydney, Australia. No source was given in any of the trees for her death, though many of her other life events were sourced in some of them.
Unfortunately NSW probate indices only cover the period from 2013 to date.
Overall I think this is likely to be true (on the basis that the Ancestry trees I checked seem to be well sourced on the whole), but further confirmation needed.