They probably don't want to start sharing details on the specifics until they're closer to release, when all the big changes and general plans are finalized and they just need to tweak details.

If they said 'our plan is to do this this and this' but then during development they end up changing course because they had another idea they liked more or idea A just didn't work out in practice it may lead to confusion or people being upset because they liked the first approach etc. So they don't give us the details until closer to launch when there aren't likely to be any big changes beyond tweaking some potencies or something.