If white supremacy would stop being perpetuated, we could stop worrying about the effects of white supremacy. But the discussion doesn't have to end after a specific timeframe just because you feel uncomfortable with it.
A society with severe imbalances in wealth, health, and power should examine how those imbalances came about. If it turns out that they're directly caused by racism, that society should consider race-conscious remedies. This is true regardless of how long the racist policies have been perpetuated, and it's true regardless of whether or not the federal government of the USA still exists.
My only disagreement was with the conclusion that such remedies should be ordained at this moment to be "always be a topic deserving of special dispensation" since always is a very/infinitely long time.
You design one for its ever-lasting nature.
You design the other to achieve a specific outcome.
Reminder that even the oldest of official policies in the US are just over 300 years old. Two magnitudes less. Most policies currently in use are less than a hundred years old and are a result of changes and amendments to those that proceeded them.
Even common law is only a thousand years old and has been revised over time.
None of that has anything to do with the issue still being relevant now and for the foreseeable future, ie the colloquial definition of “always”. When that eventually changes, then it can be re-evaluated, but that’s not likely to happen within our lifetimes, so it should very much be remembered when policies are made.
If we can do that in 50 years (doubtful) then we can stop talking about it. Ditto for the other time frames you mention.
Even then, we shouldn't really stop talking about it. Forgetting our history increases the likelihood that we'll slip back into old patterns and do it again.
Further, humans are social primates. As books like DeWaal's Chimpanzee Politics demonstrate, power hierarchies that seem very familiar predate humanity itself. It's perfectly possible that violently enforced group hierarchies are a natural outcome that can be based on any sort of visible difference. Since race is such a visible and obvious difference, it's plausible that for the rest of our history, we'll have to educate people out of racial bias and put everybody on guard against the emergence of the sort of racial animosity and racial dominance that persists to this day.
I completely disagree. Still after another 50 years? Another 150 years? Still 1000 years from now? 10,000? At some point, it has to be eliminated as a special dispensation topic. When exactly that is, and whether that is in the past or the future can reasonably be debated, but to conclude that it should be permanent is well beyond reason, IMO.