When this was added to the cloud seed we changed this from "users that install LXC will loose connectivity to a 10.0.x.0/24 network" to "all cloud users do not have connectivity to a 10.0.x.0/24 network at boot" and the cause/effect will not be as clear to an end user. This had come up in conversation but had not been documented in the bug. So let us continue to search for a solution like what you have outlined in the last paragraph of comment #29.
Séphane,
When this was added to the cloud seed we changed this from "users that install LXC will loose connectivity to a 10.0.x.0/24 network" to "all cloud users do not have connectivity to a 10.0.x.0/24 network at boot" and the cause/effect will not be as clear to an end user. This had come up in conversation but had not been documented in the bug. So let us continue to search for a solution like what you have outlined in the last paragraph of comment #29.