I think this would create more problems than it solves. Dependency management/dependency convergence is a hard problem, but it is currently a problem left to downstream. The class path is ultimately the responsibility for the users deploying the software. I do not think Accumulo can, or should, take on the responsibility to handle all the bugs and compatibility issues which could arise in any one of our dependencies, which we've bundled into our project. It would also cause problems for users who are already doing their own dependency convergence, because then they would have to de-bundle.
I'm closing this issue for now, but my thoughts here are only my own. We have not discussed this much on the mailing lists. Feel free to open a dialogue at email@example.com if you wish to discuss it further, as this would be a change with big implications, and would need to have some serious discussion/debate.
In the meantime, please also feel free to continue to comment here, with suggestions for mitigations. If you have a patch to do the shading, or some other workaround for dependency convergence, posting here could be useful for other users in this circumstance, even if we don't reopen the issue and apply it upstream.