I saw that they bought the land but couldn't find any information regarding the beginning of the buildout. I know they were trying to go public via SPAC but that avenue was shut down for most. I'm not sure how they're planning to finance at this point but if they want any chance of being profitable in the US they can't continue to ship cars here.
OK, found this from this morning:
VinFast secures another $2.5 billion in funding, led by $1B from VinGroup’s chairperson alone