Man of Steel was released back in 2013 and had a 'sequel' in the form of Batman v Superman: Dawn of Justice, but there was no direct sequel to the movie. But now, we're teased with Man of Steel: Cerebral, which could feature Brainiac -- thanks for the excitement, Boss Logic.
Superman fans and myself included, hoped that Man of Steel director Zack Snyder would announce something Man of Steel 2-ish when he revealed Zack Snyder's Justice League, which will be an HBO Max exclusive in 2021 -- but nothing happened.
Now we have the team at Boss Logic teasing the world on Twitter with a simple tweet saying "Let the mind games begin #manofsteel 2" and tagging Zack Snyder himself. The sequel here in this mind game is called Man of Steel: Cerebral, a nod towards Brainiac.

This is nothing official, but it could be a nod from Boss Logic towards an impending Man of Steel sequel announcement at the online DC Fandom event that is taking place on August 22, where all things DC Multiverse will be on show for 24 hours starting at 10am PT.
We are expecting to hear about: Aquaman, The Batman, Batwoman, Black Adam, Black Lightning, DC Super Hero Girls, DC's Legends of Tomorrow, DC's Stargirl, Doom Patrol, The Flash, Harley Quinn, Lucifer, Pennyworth, Shazam!, The Suicide Squad, Supergirl, Superman & Lois, Teen Titans GO!, Titans, Watchmen and Young Justice: Outsiders.
I'm hoping we hear much more on Zack Snyder's Justice League, and maybe even a trailer... as well as some more information on Wonder Woman 1984 -- which was recently delayed, with a new release of October 2, 2020.

More reading on Zack Snyder's Justice League:
- Professor X asks Superman about Zack Snyder's Justice League
- First footage of Zack Snyder's Justice League confirms Darkseid
- Wonder Woman 1984 delayed from June 5 to August 14, now to October 2
- HBO Max is live, Netflix and Disney+ competitor costs $15 per month
- Zack Snyder's Justice League might cost much more than $30M to finish
- Henry Cavill in talks to continue as Superman for the DCEU
- Zack Snyder's Justice League announced for 2021, exclusive to HBO Max
- Zack Snyder to host Man of Steel Watch Party on May 20, Q&A included
- Even Batman is affected by coronavirus, The Batman production halted
- Subway tweets Zack Snyder about a Justice League sandwich
- Superman DID have a black suit in Zack Snyder's Justice League
- Justice League Snyder Cut confirmed (again) by Jason Momoa (again)
- Every Superman, Batman, and Joker movie ever made to stream on HBO Max
- HBO Max launches in May 2020 for $14.99 per month
- Justice League fan cut uses Zimmer music, improves end fight
- Joss Wheddon taking over 'Justice League' directing duty
- Batman v Superman: Dawn of Justice 4K Blu-ray Review