actually, what they said was "there are no plans for that - the only way to get the pre-order packs is by pre-ordering the game" which is slightly more binding than you suggest. The second part, that many people seem to ignore, puts it pretty clearly.
"The only way to get the pre-order packs
is by pre-ordering the game"
Note the present-tense. IS means right now that's the case, not that it will always be the case.
It IMPLIES a binding restriction, without actually providing one. They'll be free to release them later, and as I said, I hope they DO. If it turns out to happen, I probably won't be buying any of them in a hurry, but more people will be happy than will be offended by the decision. Most people these days expect pre-order exclusives to be timed these days. Especially when they include gameplay-influencing extras like guns and items with unique stats, as opposed to purely cosmetic extras.