It could go either way, depends on the reviewing officer. One could argue that the K2 follow up was a choice by K1 holder and was foreseen well ahead of the k1 interview and so not eligible for the expedite. The other could argue that since k2 has to immigrate within 12 months of K1 visa date so could be eligible depending on how long it's been.
Did you provide anything? Unless uscis sees an interview appointment for K2, it may not see a reason to expedite even if it wants to.