The user interface change puts all of the extension icons to the right of the omnibar. Ones you have hidden get put into the hamburger menu—unlike before, you can’t hide the extension icons completely.
Google says this is to protect users:
We’ve heard too frequently that many users are unaware of the extensions they have installed, whether this is due to sideloading, installation by phishing, or simply the user forgetting how many and which are installed. Unfortunately, extensions consume computing resources, and may have significant security, privacy, and performance impacts. Because of this, we’ve decided we need to increase user visibility.
Perhaps it’s a good reminder to clean up your installed extensions.