He's trolling for sure. The cards are a simple demonstration on how easy it is to distract the media and have them report on what he wants.
The 'Major Announcement' is right here.
https://truthsocial.com/@realDonaldTrump/posts/109518990392565381
https://stopworldcontrol.com/fuellmich/
Dr. Reiner Fuellmich is an international trial lawyer who has successfully sued large fraudulent corporations like Volkswagen and Deutsche Bank. His worldwide network of lawyers has listened to a hundred (meanwhile 200) experts from every field of science. They have collected undeniable evidence that the Covid pandemic is in fact a planned criminal operation. According to Dr. Fuellmich, a second Nuremberg trial may be needed, to prosecute all who are complicit in this unprecedented crime against humanity.