Conversation so far:
Why did Sotelo leave the band From First to Last?
Spencer Sotelo left From First to Last  because Sonny Moore was going to return to do the vocals.
Did Sonny Moore reunite with FFTL?
On January 15, 2017, From First to Last released a new single, Make War, featuring vocalist Sonny Moore.
What is From First to Last doing now after Sonny Moore's return?
In December 2017, From First to Last debuted a new song entitled Surrender at Emo Nite Day in Los Angeles.
Is From First to Last going to tour now that Sonny Moore has returned?
From First to Last is set to return at another Emo Nite LA event this March, marking just over two years since their last performance.
Was Sotelo leaving From First to Last an issue with the other members?
According to Sotelo, From First to Last did the album Dead Trees for fun and had no intentions beyond this.
Are there any other interesting aspects about Sotelo leaving and Sonny Moore rejoining From First to Last?
On July 30, 2016, former vocalist Sonny Moore held a radio show on Beats 1 as Skrillex.
Did the From First to Last band members do anything else besides the radio show to suggest their return to music?
The final song of Skrillex's Beats radio show, an untitled bonus track was, according to Alternative Press, reminiscent of prior From First to Last work with Moore's vocals.

Question: Did the Bonus Track ever wind up on an album?
Self-contained rewrite: Did the untitled bonus track Sonny Moore debuted ever wind up on an album?