I don't think you're on the right path, didn't Avita re-domicile...

I don't think you're on the right path, didn't Avita re-domicile as a company to the US?
This is nothing of the sort. My understanding is that OPT is simply listing depository instruments on the NASDAQ that are, more or less, a mirror of OPT on the ASX. OPT remains an Australian company and it's a relatively low-cost, low regulatory path to open up a huge pool of potential capital.
Of course US investors could simply buy OPT shares on the ASX, however I'm sure there would be many US-based funds etc that are internally restricted to US based holdings. I would also think that US-based shares gather more US-based interest.