DTT are happy to provide general info about ZC19 anytime and any major developments are announced widely via the railway press (I have previously submitted articles to Railway Digest and Motive Power announcing the securing of this loco).
However, discussion about specific society plans, proposals, etc. are not for public dissemination, as a lot of society officer's negotiations with the various organisations and authorities we are dealing with are quite sensitive and any public announcements would jeopardise these negotiations and the aspirations of the group.
Members are kept well informed about developments, through meetings, minutes and reports, etc. Hence the comments that if anyone is genuinely interested in whats happening, membership is the best way to keep up to date.
I recognise positive publicity is a good way to attract new members and anything that is cleared for public release will be announced without hesitation, but as I mentioned, that cannot happen if it means potentially undermining DTT's relationships with the entities it is dealing with.
The absence of public announcements doesn't mean nothing is happening. I am as impatient as anyone to provide more positive news, but unfortunately, a small group of volunteers doing their best to professionally deal with some major organisations is a frustratingly slow process. Of course, more supporters can help speed things up!