I think it's best they forget superman of the DCEU, i really do (and i liked MOS and love Cavill, the suit the cast etc) It's just been too long in the tooth and if die hard fans like myself are ready for a reboot, or at least bored of this one, then the GA are not going to care as much.
A movie needs to start filming ASAP to stay relevant. Otherwise..
WW1984, if good will get a sequel and that can be another period piece so maybe the 90's or early 00's where she basically works alone. That's then a WW trilogy with BvS and JL to her credit.
AM, if good, may get another sequel - again, that can be self contained, under the sea.
Shazam, the sequel will involve the Rock - have fun with that and will be self contained. Nothing needs to interfere or take it away from their universe - the justice league are all out there, it's just not focused on - it's a shame, but the movies will stand on their own merit.
However, i have said this before and will undoubtedly say it again - from MOS to BVS we had what 2 years? There are two movie worthy stories in there.
Get Cavill back in the MOS suit, get him back to that hopeful tone at the end of MOS and push forward with how that Superman is seen.
My idea - years before Superman was revealed, an alien life form was captured on earth and like Kal El, was seized and interrogated - unfortunately this one was badly damaged so was hooked up to all types of monitors for tests - coma induced, picture a big water filled tube, creature in stasis etc. From this creature and craft a lot was refer engineered and a lot of todays tech came from it, as well as AI.
This creature was literally being harvested and used as AI for governments, algorithms etc and like skynet, it will turn bad.
We see Clark adapting to life post superman reveal, the world loves him, some ofcourse don't - we see one public figure condem him.
Lois and clark, upon their own research of meta humans, plus whistle blowers coming forward, linking superman to this other creature, find the location of the facility - once there, superman explores to learn more and demand it be shut down, to free the creature - the AI doesn't allow it, it's almost as if the creature is where it wants to be. The creatures eyes open and communicates for the first time, via AI that he is brainac and his mission on earth is nearly complete - to show his power, half the eastern seaboard shuts down - no power at all, it's disaster, like the purge almost, power stations on red alert etc
Superman has to go off, help the military calm the cities, stop the riots etc. Some cool montages of fires put out, mobs calmed down etc. Enemy nations look to attack u.s soil in its weakened state, it's tense.
Superman returns but the facility has been demolished - the creature gone. In liaison with lois, norad and the army, general sam lane, they track an orbiting satellite - superman flies there - a massive skull ship, behind the moon, mile high pods are hidden, all linked to the skull skip - creatures are in these crude pods.
superman negotiates - the AI 'leaves' earth, everything back to normal, yet no one knew why, what or how.. society is none the wiser and just look at it as a freak incident.
Up on the skull ship, Superman is the bargaining chip - he has to stay, as Brainiacs specimen of the last son of krypton - he is lead to a large, glass domed pod and is led there on the ground, of what looks a kryptonian, female.
The sequel, MOS3 is then the escape, reveal of Supergirl and the reveal of the multiverse.
