No, dbl would just promise a hand that could handle a 2♦ rebid (either by passing, bidding 3♣, bidding 2♥, or having invitational+ values). You're logically inferring, but it doesn't say that. Do you really go through your head before making a double "if partner bids 2♦, check, 2♠, check, 3♦, check" or do you just say "yay 4 hearts double!" are you saying you don't?