The Shape of the Arch

[SkurjMaster]

Dear All,

Please forgive me if this is unoriginal, but I noticed something in my reread of Fatal Revenant the other day that I think I missed the first time through. There has been some mention of an arch vs. circle design (I think) somewhere in the Watch, but this was different. Shortly after Linden and 'TC' arrive in the past, 'TC' makes the statement that the Elohim are afraid that he 'will change the shape of the Arch.'

Is it possible to change its shape and still call it the Arch of Time?
Can TC really do that?
Or, is something being hidden here? Maybe Jeremiah can change its shape?

What do you guys think?