The reason why Nancy Pelosi didn’t hold a Full House vote to initiate an ‘Articles of Impeachment’ inquiry is simple: if she did follow the formal process, the minority party (republicans) would have rights in the process; so too would the executive branch.
By subverting the process, and just arbitrarily decreeing the opening of “an official impeachment inquiry”, Pelosi allows the committees to proceed without any representation by the minority in the investigative process.  This approach, in combination with the 2018 rule changes, is a feature of the impeachment plan – not a flaw.
Against that backdrop, this set of tweets by President Trump have much more meaning:

The House of Representatives cannot construct articles of impeachment through the utilization of anonymous accusations (ie. ‘whistleblower), and hearsay.  These tweets are not just POTUS lashing out; these tweets have a very material purpose…
MORE HERE and more to follow.