继续请教求职邮件

Congratulations! The Company would like to invite you to continue with the next step of the hiring process, which is a telephone interview for the () position. Please click here to self-schedule today. Schedules are limited so please schedule as soon as possible.

今天接到这个电话INTERVIEW的邮件, "Schedules are limited so please schedule as soon as possible", 什么意思? 难道他们有一堆人, 成百上千的, 要打电话, 预约晚了就没份了?

谢谢!