As of today Kansas City, KS, KC Central, MO, and the South Kansas City, MO areas have been opened for sign-ups indefinitely. Only fiberhoods that met their goals during one of the previous rallies in those areas are eligible to signup though.
This change may have been because of this letter that Rep. Emanuel Cleaver (D-Mo.) sent to Larry Page (CEO/cofounder of Google) on February 5th, 2015.
This news site made the link that these two events might be related: