The Hideout just shows a blank map, so it's not possible to practice mirage ult teleporting to allies or enemies while in the hideout.
Even just showing the character portraits on the background texture would be an improvement as a stopgap while a map is made.
This issue is still present following the 3/6/26 rework of Mirage's ultimate - but now the hideout would actually require a graphical minimap (even if it's just a basic outline of the playable space) in order for the ultimate to work.
