Joe muses about Xlib and connection aborts. Two things:

Yes, libX11 is going away. It's unfixably broken (not only is the implementation utterly horrendous, but the concept is exactly what toolkits don't want), and we can't change existing behaviours because libX11 is just one of those API/ABIs you cannot break.

Yes, the ability to recover from connection aborts is essential. D-BUS is broken in the exact same way, yet some people feel inclined to defend it (e.g. mandating reboots when either of the D-BUS daemon, or libdbus, are upgraded; advocating segfaults in client applications when the bus dies as the right thing to do?!?). I don't think either behaviour is in the least bit sensible, and it would be really keen if both could be fixed (by using XCB in toolkits for the former, by fixing libdbus to be less obnoxious for the latter).