Unfortunately, websites can still detect if you’re using Incognito mode which in some cases can lead to them blocking users from certain websites, which obviously is not what Google had intended. So much so that in a series of commits made to Chromium’s Gerrit, Google is now making it harder for websites to detect if a user is browsing their website in Incognito mode.
What Google plans to do is that in the future when a user is browsing a website in Incognito mode and when the site asks for a file system, Chrome will generate a virtual one using your computer’s RAM. This means that when you leave Incognito mode, it will be deleted which should ensure that each and everytime you use Incognito mode, it will be a “new” session.
As to when this feature will arrive, it is expected to arrive in Chrome 74 behind a flag, meaning that users will need to enable it manually, which means that it will probably be several versions later when it should be available to all users by default.