Number ranges can overflow, they usually automatic start again with the first number in the range if you ignore all messages. The reason for this is that they often got defined without farsightedness. I seldom saw a case that it was impossible to find another space for a new range, but it can happen, then you take the risk that something strange can happen.
It would be quite a big work to find any or all SAP notes, but this is probably unavoidable if you really need to reset a number range. I just searched with: archiving "number range" and got 337 hits
I just picked randomly one and have already found a killer note
167155 - Archiving of Notifications
As you can read, in this case is no solution given at all.
But honestly, the purpose of data archiving is really different from making space to reuse a number range.