From Trip Advisor and others I know, there are apparently only two rail operators worldwide refusing refunds 'due to COVID-19' circumstances.
Journey Beyond is one (Australia) and the other is in a similar jurisdiction with also a Westminster system of government, Rocky Mountaineer in Canada. Both have attracted a lot of negativity on TripAdvisor. While review sites gather the disgruntled and give them a voice, both deserve the adverse feedback. A number of the RM 'anti' reviews are from Australians, perhaps unsurprising given so many of us don't just dream of a visit but travel there.
(In contrast, government owned Canadian rail operator Via Rail offers refunds for its flagship train 'The Canadian' and other services like 'The Ocean'). The latter two (especially 'The Canadian' are great journeys that I found most enjoyable). No off train dining!