Flooring grade chipboard normally has a 'printed' side and a 'plain' side. Last I used was from Wickes & it was 'printed' side up.
If you are still worried about the T&G short joint not being directly over a joist, stick a few noggins in across the middle.
Hasn't anyone wondered WHY they machine it with T&G on the short edges? If it was intended that the short edges were going to be over joists they might as well leave them square & save the machining costs.