Just to clarify, Greg Newby was not the CEO of Project Gutenberg, which was founded in 01971, but of the Project Gutenberg Literary Archive Foundation, which he founded in 02000 or 02001. It has contributed immensely to Project Gutenberg, but they are not the same thing. Newby would never have attempted to take credit for PG.
I've become an unironic proponent of HE, the Human Era. For CE dates, we just add 10000 (I'm writing this from 12025). But for BCE dates, they're subtracted and it makes things so much clearer when it comes to telling how long ago something was. E.g. the sundial was invented around 6000 HE, steel was developed around 9000 HE.
1. Pick an epoch date so far in the past that nothing of interest could possibly have taken place before it.
2. ???
3. Profit!
The two problems with this idea are, first, that everyone argues about the exact value of the epoch; and second, that something always ends up having happened before that.
You can also invert the scheme, to get the Before Present system. This has the same two problems (s/before/after/).
It's better to call this Holocene Era even though Holocene didn't exactly start in 10,000 BCE, because modern humans were around for a long time prior to the 10,000 BCE epoch. Some people have proposed 8,000 BCE as an epoch, styling this "After the development of Agriculture". According to this epoch, we'd currently be in year 10025 A.D.A., which is neat.
An unfortunate suggestion of that nomenclature is that it suggests that "humanity" came into existence only 12025 years ago, which would mean that the creatures before that time were all non-human. This is especially unfortunate given that it strongly implies that, for example, either Khoisan people, Australian people, or European people are human, but not more than one of the three, since they diverged genetically before that date. While, on one level, this is merely a semantic issue about the definition of the word "human", on another level it mirrors the ideological justifications for mass enslavement and genocide that caused historically unprecedented atrocities in the 20th century (unsurpassed until Mao surpassed them), because most people's ethical systems accord special privileges to "humans", for example holding that killing any number of nonhumans is justifiable if it saves even one human's life, or, in most cases, even if it merely provides them with meat to eat.
While I don't believe the Kurzgesagt staff endorse genocide and cannibalism, I think they may not have clearly thought out the implications of their choice of terminology.
Premack's timeline that you link does not make the same error, calling it the "Holocene Era", as Emiliani did.
Edit: the post title has been fixed now.