As you requested, I reread what you wrote. I still don't think of the ToT as a park icon. As a matter of fact, the DHS icon mess needs to be addressed in the new build.
All the other parks have one single icon per park. It's clear in each park. In DHS you had the water tower, then the Chinese Theater and then the BAH. And Disney itself created this mess. And yes even the ToT was used to advertise the park and play the icon role. It just goes to show how badly DHS needs a central icon.
By changing the appearance of the ToT it would help to erase the old image and allow DHS to create a new icon for the park that would not be confused with all the previous "icon of the month club" attempts. The current ToT looks like a horror hotel that Disney made to compete with Universal.
But moving on from the icon problem, I see no reason why the building would really need to be changed. I don't think it would be a problem for the GotG crew to show up in a 1930's Hollywood hotel and save any number of galaxies, universes, time warps and other dimensions from total destruction. And I'm sure that both Groot and Rocket Raccoon could carry out such a mission with good humor as well and make it all family friendly.
So there you have it. We can change the appearance of the building or leave it the same and that solves the appearance problems. As for the Twilight Zone problem, I've always wondered how a 1960's TV show doesn't ruin the "theme" of a 1930's hotel. The answer is of course that people will overlook anything if it fits their notion.
Therefore if a 1950's TV show can show up in a 1930's hotel, then it's not a stretch for GotG to show up. Time travel is common place with the new iPhone and android devices. All the kids know that.