The introduction of new perks can be seen in a number of ways:
a) They are getting their perk fetish out of the way before Halo (5) One. Halo 4 has a declining population, so why not.
b) They are testing these new perks for Halo (5) One.
c) Space Jesus vs Mechs. Guillermo del Toro directing.
d) Perks are now canon, because of nanomachines and ponco wearing space corgies.
ding ding ding