Observed data: Why so many MPECs about TNOs lately?
This is the result of a new way to investigate the images taken by the PanSTARRS survey, see
Weryk et al. 2016.

A second batch of new discoveries was issued on July 26.
This has been planned for several years, and now there's enough data to get useful results.

Note that Gareth Williams from the MPC has currently some technical problems with the most recent MPECs (O360 and higher). If these links don't work for you, it's probably because of that.

For further information, see
the PS1 Science Consortium blog
and Holman et al. 2015.