There are basically three things that France can now do:
a) abandon New Caledonia entirely. This may happen anyway, as an independence referendum is scheduled for December and the balance is uncertain;
b) join AUKUS as a junior partner, very painful but logical;
c) embrace China out of spite or as a result of different geopolitical calculus. That would probably have significant realignment echos in Europe, because France has a big voice in the EU. I am a little afraid of this scenario, though I consider it unlikely to happen.
Edit: I remembered that Tahiti is at stake too. Not certain about local independence movement status.
a) abandon New Caledonia entirely. This may happen anyway, as an independence referendum is scheduled for December and the balance is uncertain;
b) join AUKUS as a junior partner, very painful but logical;
c) embrace China out of spite or as a result of different geopolitical calculus. That would probably have significant realignment echos in Europe, because France has a big voice in the EU. I am a little afraid of this scenario, though I consider it unlikely to happen.
Edit: I remembered that Tahiti is at stake too. Not certain about local independence movement status.