Craig Wright and wife, Romona Watts, with possibly their children, are now residing in the UK.
So? Paul Hogan has lived in the US forever but there was still a high profile court action against him by the ATO which lasted for years.
The UK isn't a barrier to either administrative or criminal action against Wright, and he clearly still has assets in Australia. The UK will extradite, and if Wright is on an Australian passport he's kind of screwed because it can be easily frozen in the event of insolvency and/or criminal charges.
The ATO has considerable coercive powers, as does AUSTRAC.