Rather unsurprisingly, Microsoft have confirmed that the original HoloLens will not be receiving the May 2019 Update or future version of Windows. The v1 HoloLens launched back in 2016 and is powered by an Intel Atom processor so it’s no surprise that Microsoft now focuses on the much more powerful v2 HoloLens. It will be receiving security updates and bug fixes as part of the Windows 10 October 2018 Update, Microsoft have been releasing monthly updates for the v1 HoloLens.
The confirmation is on Microsoft Windows Mixed Reality documentation page, which the team recently updated with the details of the May 2019 Update for Windows Mixed Reality (after a little prodding from me).
HoloLens (1st gen) Long Term Servicing
HoloLens (1st gen) is entering Long Term Servicing (LTS) state. Future updates will focus on issue and security fixes, while maintaining feature parity with the Windows 10 October 2018 release for HoloLens (also known as RS5).