Could those posts be reported as breaking the first rule regarding uninteresting and low value posts?
Necrobumps are usually
only acceptable when they provide something of dramatic value: to justify reactivating an old/obsolete thread, you have to bring a significant amount of depth or nuance to the discussion for revitalization.
Otherwise, what would prevent people from just sorting by last active (ascending) and making
agree-type spam posts or
generic vague remarks to regurgitate information they haven't posted before?
I will often report posts that are 6mo+ old necrobumps if they do not serve any meaningful purpose.