You're right! HERE is gone from the store.
For what it's worth, I have both HERE and Microsoft Maps loaded on my 1520.3 running 10586.36, and after checking them out, I elected Microsoft as the better option.
(What I'd really like is fully functional Waze. But Google, who owns Waze, long ago announced they are dropping support for a Windows Mobile version of Waze. C'est la vie in corporate combat.)