The government could put it's decisions and publications on a website, official, verified, more or less controlled by them. There's no reason that has to be done with consultant scams - oppositely, posting on Twitter doesn't guarantee consultants aren't raking in money for adding or removing periods or whatever.
But I guess its easier to just complain about Twitter.
What do you mean? How would anyone not affiliated with a given government agency convince human verifiers at Twitter that they're official?
If you don't snatch up your (organization's) name first, someone will surely do so for you.
(Honestly not trying to incite anything by using him as an example; I just hardly use Twitter and he was the first to come to mind.)
Yes, but this account will still not have the same legitimacy. Right now, if Trump tweeted a declaration of war, it would have been reasonable to assume that it was real, because, for all we know, it's an official channel. Previously at lot of people would've at least checked back with the official channel before taking it for granted.
And, to make matters worse, having Twitter as an official channel now gives everyone at Twitter the possibility to make official announcements - hardly a good state of affairs.
"Maybe government should embrace popular communication media instead of spending billions on custom IT infrastructure to post a message on a custom page that everyone screenshots and copies to their timeline anyway."
(Also if they don't create an "official account", someone else will do it for them)