Well it is certainly a secret area present within the game. Immortality, space travel, etc. are not prohibited by the laws of physics. And saying that getting from here to there within the next 40 years is actually impossible (as opposed to very difficult) sounds pretty loony to me.

Some players have been paying a premium monthly subscription for years in a hope to get the expensive future upgrades promising priority access to the area when and if it is out of beta.

This is an argument for working towards posthumanity in general, not giving money to specific groups working towards posthumanity. The argument is supposed to work even if no such groups exist. (If you don't know of any good groups working towards posthumanity, that's pretty much the same scenario.)

The idea is to reframe working towards posthumanity as an expected value calculation, since it's hard for our brains to think well about totally unprecedented outcomes (i.e. black swans).