Yes, the Supreme Court can do away with a certain part of the Voting Rights act due to there being less racial discrimination, because the systemic problems with Voting Rights in the 1960s have largely been done away with. What is left is too much oversight, where the federal government can make it very hard for some places to have elections.
I definitely think that the Voting Rights law should stay the same despite there being less discrimination. I do not think that the Voting Rights law significantly give certain groups of people an unfair representation. While I do agree that some policies in today's society should be done away with, Voting Rights isn't one of them.
I believe it is wrong to assume that racial discrimination in voting is 100% fixed in the United States. There is no reason for the Supreme Court to do away with these laws. If the problem is truly solved these laws could stay on the books without concern because they wouldn't be cited. The truth, however, is the fact that these problems have been addressed, quite recently.
Regardless of the actual levels of discrimination that currently exist, voting right protections need to be in place to ensure that they do not come about, or that there is remediation when a violation does occur. If they were to be taken away, these abuses could occur unfettered, which would be wrong.
I don't think the Supreme Court should touch the voting rights act in any way, I think it would be a grave mistake to think that just because there is less racial discrimination today we should strip out the provisions that deal with that issue, we don't know what is going to happen in the future.