Standard Election Year Pandering 101. Even from Trump. And of course from Bernie as well.
Understand this. The American President is not a king. He has to work with the House and the Senate.
He can lay out what he would like but unlike Obama (or Cruz) he will not use Executive Orders to run this country.
He has a tax plan that he believes will be best for this country - he is also a realist and accepts that this will be changed as he works with Congress to get what he wants.