It was quite obvious if you have read recent articles of Microsoft about Lumia. By redirecting Nokia online properties to Microsoft.com and by calling their phones just “Lumia”, the Nokia has been gradually shut down. Soon the lineup will become “Microsoft Lumia” after the expansion of this re-branding effort.

Lumia accounts for almost 90% of the market and thus the de facto feature of Windows Phone. The big names mostly have neglected WP and though MS has been busy signing up new vendors but it will be difficult for the company to achieve major market share.

Nokia replaced with Microsoft

Nokia still exists as a company but it would not be able to make new phones for several more years due to its agreement with Microsoft. Since then, it has been bringing its software to Android and focusing on other things such as mapping.
We have to see whether a moderate Lumia logo will be enough on the device or Microsoft is going to put its own logo there. It should be remembered that slightly advancing by showing preference to Nokia in order to not annoying other WP vendors.