the elders that remembered their history were killed and people isolated

This happened a lot. Religion and wars had lots of conflicts with history. What's in vedic traditions originally passed orally have some serious astronomy records that happen 1 after next. These stuff leads earlier than last ice age.

This iceberg video is really good. But even that's missing some info 👇

Then we have this video that get everything completely messed up.

IVC script is written sanskrit in abugida script. It's actually a later form of sanskirt with many features missing from vedic sanskirt. IVC was from 7000 BCE to 1300 BCE according to archaeology. 2600 - 1900 BCE is given as the mature phase. IVC script was used to write CLASSICAL sakskrit at this time. We don't have much archaeological evidence before that.

Since Brahmi is just an evolution of IVC abugida everything related to Brahmi should be called a descendant of IVC abugida. It's generally accepted that abugida is a late invention. IVC script may have older versions. We could even be looking at a post apocalyptic world trying to reinvent some of their old tech.

These are some of the coolest stuff I've seen