Not really, I fear. I'm unable to reproduce this. Have tested both with the
current X2Go nx-libs release builds and Mike#2's copr repo for the arctica
version. In both cases MATE starts up without segfaulting in xcb.

However, for some reason I even have direct rendering available in the session.
Merely through MESA's software renderer, but still working fine.

I can even disable the GLX extension. In this case, direct and indirect
rendering are not available, but MATE is still starting up correctly.

People have suggested that libgles1/2 must be available on the system, so what
about:
rpm -qa | grep mesa-libGLES

It's there:
rpm -qa | grep mesa-libGLES

mesa-libGLES-17.2.2-2.fc26.x86_64

Anything else I can provide?

Did you see my separate email about the X2Go session losing focus and having to click some where on the screen to resume, even when typing in emacs? This is on the good server.