If he had anything worthwhile to declassify, he would have done so already. What good will it do to wait until his last 2 weeks in office?
Who’s going to actually ACT if and when Trump gives an order to de-classify? The classified info is undoubtedly controlled by Intel agencies, and to date, not one of them has shown a drop of willingness to do diddly to support the President.
I’d wager any order to de-classify would be met with the usual bureaucratic delays, if not outright hostile objections.