The book is pretty clear on time being immutable, and I think changing that would be a bridge too far even in a post-HJ race 'retcon' show.
The pieces on the table related to the tower are Nostalgia, mind control, the free HDTVs, and whatever it was that crashed where the tower now stands. Even if the backstory stuff like Tulsa, Vietnam/the My Lai not-massacre (hometown of Trieu's 'mother'), etc, shaped the worldviews of the characters, I don't think that the massacre could be the impetus for the tower in Tulsa when the tower is built exactly on top of whatever crashed, unless she had chosen for it to crash there. But if she had done that, she probably wouldn't have had to strongarm the farmers.
"It tells time" from Trieu's daughter to Blake is still the giveaway. It has to be some sort of broadcast tower, and the question that raises is whether Trieu's intentions are malevolent/vindictive or benevolent but misguided like Ozymandias's.