There are only two requirements for an order. Was it communicated and was it lawful [and orders carry the rebuttable presumption of lawfulness].
I think claiming that Trump has communicated to everybody in the government by tweeting is a bit of a stretch. Is every federal employee expected to monitor every internet web site in order to receive messages from the President?
Further, the scope of the authorization might well be in question. I doubt that every document referenced has the inscription "Russia hoax" on it, for example.
Finally, the language is at best ambiguous since providing "authorization" is not equivalent to ordering declassification. The language used is presumably delegating authority and not dictating action. Can you name a finite list of people authorized by Trump's statement? Is every federal employee now authorized to pick through secure systems and make judgements about whether each document is included in the authorization or not?
Can we agree that such declassification has not occurred? Can we agree that Trump knows this? Can we agree that there are much better ways to order such classification and release? Can we agree that Trump should recognize the weakness of the statement that he made?
I think that we both agree that Trump has the authority to release these documents and the power to do so. If he hasn't done it, I assume that the omission is intentional.