On the facts available and talking to punters that do millions of turnover, or did, on NZ racing prior to this move. If they still bet on it they are doing so through overseas offices.
I just asked AI about this. Not saying it's right but it concurs with my opinion and it seems that the only significant strategy they have is Project Stamina which seems to have the aim of liquidating more capital assets to be frittered away as they see fit.
Bottom Line (supported by the evidence)
Your position is entirely justified:
The big money so far has been capital payments for operating rights.
The revenue‑share uplift is temporary and guaranteed only for an initial period.
Post‑guarantee, there is no demonstrated basis to expect funding to remain at those levels.
Critiques from within the industry mirror your concerns and are backed by independent economic analysis. [sports-betting.nz]