/e/ browser was originally based on Bromite (fork of Chromium). But Bromite project was stopped one year ago.
So, they have switched recently to Cromite browser which is still a fork of Chromium.
/e/ is making a new build approximatively every month so I guess they will try to update their browser regularly.
But the /e/ browser will be probably delayed by minimum one month from latest Chromium version available (due to test and integration time process).
In case you need an up-to-date browser, get it from F-Droid or Aurora Store and update it by yourself.