This is a good reason to never prefix generated Javascript with hex hashes, at least without swapping out vowels. We rolled the dice one and had this happen on Wikispaces once; it was utterly infuriating to debug.
Nice catch, never thought about it. Is it more problematic with preffixes (vs. suffixes etc.) or should we generally avoid any random string? Appending a hash to the script is very convenient to force the download of the new version of an asset (but maybe we have better solutions now, haven't considered this issue in a while).
You can also do /js/myscript.js?v=1476929634 -- this generally works without any server-side changes. A CRC32 might work better, since controlling mtimes can be annoying.
Why is there a problem exactly? It seems even if hash contains "ad", uBlock origin is not blocking it. Does this problem exist for some specific ad blocking software?