Although Andy Rubin's company is now up for sale and the chances to see a second Essential Phone reaching the market anytime soon have just evaporated, the company recently announced that its only device will get 2 years of updates and 3 years of security patches. Sadly, these timelines could change if Essential gets a new owner.
https://www.notebookcheck.net/Essential-promises-2-years-of-updates-and-3-years-of-security-patches-for-the-PH1-handset.306004.0.html