It it doesn't mean that, why not say "up to 2 months PTO"? If you say "unlimited" and mean "limited", then yes, it needs a footnote, just as if you said "we're going to pay you $200K per year" but then paid only half and said "what, are you crazy? I'd never pay so much as $200K, surely you know I didn't mean this, do I need a footnote over every tiny thing?" No, not every, only in cases where you say one thing, but mean completely different one.