Are there many undocumented/untranslated primary sources from antiquity that will shed light on ancient civilizations (Rome, for example) once we get around to translating/deciphering them, or has everything already be scoured by historians through the ages?

by IAMARobotBeepBoop

Is there the possibility of major discoveries occurring in this century based on further study of primary sources that we already have (excluding new documents that are dug up from new archaeological sites, for example)?

smiljan

There are documents that were previously unreadable due to damage that, due to new technological advancements, are becoming readable.

For example, a library of Greek philosophy was found in the ruins of Pompeii. The scrolls were so badly damaged that the first discoverers mistook them for charcoal. Now, with CT scans and multispectral imaging, many of them are finally legible.