We will be pushing a patch live tomorrow. Players will be returned to the title screen from their activities and then be required to log in to Destiny again after installing the patch.
I launched a Raid/Nightfall strike and I didn't matchmake.
Raids and Nightfall strikes are Fireteam-specific missions, and are not matchmade activities. If you launch into a Raid or Nightfall activity without a Fireteam you will launch in solo; be sure to grab your friends before jumping into these activities!