I don’t recall ever encountering an explicit “you can not exceed a vacation longer than X” policy- but most places I’ve ever worked have had a policy that generally sums up to “if you’re going to be taking a long vacation we need to review/plan around it a little differently than the typical process”

I took a month off for hunting and camping a few years back (possibly a decade ago) and what it amounted to was: go document the little things that no one knows you do to keep the ship afloat and cross train this guy in how to do it.