Maybe you'd be interested in PR #5092, i made a small patch to add this
functionality to tail(1) some times ago (but it doesn't work with
directories iirc) :
http://gcu.info/~gaston/openbsd-tail-follow-multiple-files.patch
Thanks for the contribution, but I don't think we want to fundamentally
change how a "standard" utility like tail works. The downside of doing
so is that people come to depend on it, and it breaks when they move to
other systems.
Having it in ports makes it optional, of course, but people know that
it's not part of the standard system.
