Does a card have a keyword if it has the same effect as said keyword?
so can I assume the card states "Surveil 5" instead? And if so, does it trigger abilities which state "Whenever you surveil ..."?


Nope, the Oracle text is leading. In general, cards from earlier editions don't retroactively get 'keyworded'; the only exceptions so far have been evergreen keywords like lifelink, vigilance, and shroud; block-specific keywords like surveil only apply to cards from that block.