No most of them are toast. Because most racial slurs are basically slang and slang by its very nature is a temporary add-on to the language. Some slang, and some slurs, lives on for many years, but most shows up for a couple of decades and then goes away.
Not true at all...the "n"-word has lived on for centuries...I know for a fact that "Polack" has (even though Wiki doesn't include the spelling, "Pollack.")
The ethnic slurs between France and Great Britain are legendary for going on for centuries. See Wm. Shakespeare.
I could go on and on down that list.