Jothar,
As an MO, I’m pretty sure I can tell you you’re missing the point. There’s no sympathy for Avi Weiss in the MO community and certainly in the MO Rabbinic community (i.e. the people who could split the RCA). What there is is a strong sense among the left wing laity that Rabbinic leadership should be doing something and isn’t. If I were to guess, I’d say the future isn’t a split in the RCA, it’s the breakup of some of the larger RCA shuls, with some of that membership forming congregations that would not be considered Orthodox.