This has to just suck for the Imagineers involved as well as Disney. Regardless of how you feel about Trump, we can all agree on one thing: it is extremely rare to find a person who has mixed feelings on him. People either hate his guts or admire him with pride. But Disney should take cues from the majority, including globally as WDW sees international visitors and have the president not speak.
If he doesn't, Disney can choose to abstain from much comment other than, "we were unable to reach the President in time." DJT may tweet, some people may threaten to boycott... but this is not at all the first time Disney's gone through this. It would blow over quickly considering the majority opinion, compared to the headaches of years ahead mired with security constantly being called to HoP. (might I suggest a breathalyzer test for adults before entering?
)
Eliminating Trump's speech would relegate his focus to a mere 10 seconds, and that still makes me wary to even want to enter the theater with other human beings, that's how aggressive and heightened the aura around this person has become. And yes: I'm speaking about both sides to make that abundantly clear.
After all, no matter what those 5 to 10 seconds will still exist in the show until the show finally comes to a halt. Might as well get people used to it.