I am currently posting some meta puzzles, and originally planned to not mention the previous puzzles. I would then allude to it being related to another puzzle in a clue. Is this just increasing the time it takes to solve the puzzle but not making it harder? ie. It's not very hard to just look at the answer to another puzzle.
It's a good idea to not require any extra effort from your solvers than you need to. If you expect "this is a metapuzzle" to not be a big or important step, it's probably better to just give the other puzzles' answers explicitly. (But if "this is a metapuzzle" is a big reveal, or some of the feeder puzzles aren't solved yet, you don't have to give them.)