"Does legal validity automatically imply moral or historical correctness?"

No.

Example:

Imagine Parliament passes a law tomorrow.

Legally,

it is valid because it passed according to constitutional procedure.

People may still argue

it is unjust,

or historically mistaken,

or immoral.

Those are different questions.

Legal validity vs moral justification

Suppose a law says:

Property X belongs to Person A.

Legally,

A owns it.

Someone may still argue

the law is unfair,

or unconstitutional,

or based on mistaken history.

So

legal validity,

historical accuracy,

moral evaluation,

are different dimensions.

They sometimes coincide.

Sometimes they do not.