I don't know if I'm just hearing/thinking things w/o any logical evidence because I definitely don't have a background in musical analysis (although the arrowverse soundtrack makes me want to get one!), I noticed something new about the different themes in the Arrowverse today.
The Justice League theme which played at the end of Crisis on Infinite Earths when they revealed the table and had a space for Oliver is almost a direct opposite to the piece of music used way back in Season 1 of Arrow, titled The Dark Archer/It Is I Who Failed This City, which is what Oliver says after his first fight against Malcolm where he believes he failed the city by not beating him (I actually have a lot to say abt this particular theme but that's not relevant to this so i might make another post later with that...)
Now I definitely could be hearing things and I'm not sure of this at all but the two themes have similar elements which seem to mirror each other.
And this would just be another poetic way of the show stating, Oliver Queen, you have not failed this city (or in this case, universe).
(Blake Neely (and Nathaniel Blume, Daniel James Chan and Sherri Chung and any other composers who may have joined the Arrowverse composition team by the time Crisis on Infinite Earths aired), you have not failed this show. You're a wonderful composer!)