IMAP was never supported and is still not supported for external account un gmail web. And they don´t remove pop. You can use pop to access your gmail in any email client or in the app if you wish.
You didn´t understand the article. You can use your gmail with POP or IMAP. What you won´t be able to do is to use POP (IMAP was never an option) to download emails from external account into your gmail account.