It's a matter of degree. I have PHP apps which have run for years with minimal hands on them. All they need is an upgrade to PHP, which sometimes doesn't require touching the app source code at all, or sometimes requires relatively minimal (compared to my rails experience) updates to the source.
(I still do not choose to write my apps in PHP. Also these PHP apps did not use a Rails-like framework. If I were to do a big app in PHP again, I'd want a Rails-like framework. And indeed I wonder how much that would increase my maintenance costs.)
I guess they all do to an extent although I've been mucking about with web2py partly because of their "We have not broken backward compatibility since version 1.0 in 2007, and we pledge not to break it in the future" stuff.
(I still do not choose to write my apps in PHP. Also these PHP apps did not use a Rails-like framework. If I were to do a big app in PHP again, I'd want a Rails-like framework. And indeed I wonder how much that would increase my maintenance costs.)