Its a pity that sysroot support is disabled and will not be enabled. In fact this is a major and serious obstacle for our company and puts spokes in the wheels for an upcoming software release. Now we need to find or configure an alternate toolchain.
The beauty of Ubuntu's armel-cross was that is was configured with libc & friends equal to the native armel target, making it a decent cross compiler for an Ubuntu target environment. To use the cross compiler in this manner, you'd need the support from sysroot to properly build and link applications (outside of xdeb) which won't get confused when running on target.
So, if the sysroot setting is gone for good, then I'm very sorry, because this was something we really needed.
Are there any commercial parties tied up to Canonical etc. which can make a toolchain with sysroot enabled on request?