The Supreme Court has not ruled on this issue. An appeal of a lower court's ruling on this issue was appealed to the Supreme Court but the Supreme Court declined to accept the case.

The Supreme Court has "original jurisdiction" over some types of cases, which means if someone brings such a case to them they have to accept it and rule on it, and they have "discretionary jurisdiction" over many more types of cases, which means if someone brings one of those they can choose whether or not they have to accept it. AI copyright cases are discretionary jurisdiction cases.

You generally cannot reliable infer what the Supreme Court thinks of the merits of the case when they decline to accept it, because they are often thinking big picture and longer term.

They might think a particular ruling is needed, but the particular case being appealed is not a good case to make that ruling on. They tend to want cases where the important issue is not tangled up in many other things, and where multiple lower appeals courts have hashed out the arguments pro and con.

When the Supreme Court declines the result is that the law in each part of the country where an appeals court has ruled on the issue is whatever that appeals court ruled. In parts of the country where no appeals court has ruled, it will be decided when an appeal reaches their appeals courts.

If appeals courts in different areas go in different directions, the Supreme Court will then be much more likely to accept an appeal from one of those in order to make the law uniform.