In fact, Jodo Shu and Ji Shu also called themselves "Jodo Shinshu" or "Shinshu" once, and Kyu Ikko-ha of Ji Shu (the founder: Shunsho IKKO) was called "Ikko Shu" once.
ちなみに浄土宗や時宗でも自らを「浄土真宗」「真宗」と称した例があり、また時宗旧一向派（開祖一向俊聖）を「一向宗」と称した例もある。