Map storyline speculation

Okay, so I did a quick analysis of the maps in OW and the storylines behind'em.
Obviously it ignores the things like hero comps and all, because that isn't canon anyway.

Assault

Hanamura:

• Ancient home of Shimada Clan. They recently got booted from there by Overwatch, and since Overwatch is now goners, I assume it's currently contracted to some PMC like Helix.
• If that's the case, the most likely scenario is that attackers are Shimada warriors trying to retake their home, while defenders are employees of whatever PMC is stationed there. Alternatively, attackers might be whatever criminal organization there is that either tries to gain a foothold in Japan or win over Shimadas' favor. Talon comes to mind.

Temple of Anubis:

• Facility contracted to HSI, some AI related research.
• While never stated outright, I think it's also the prison of the Old God Yogg-Saron the housing of the "god program" Anubis shown in Mission Statement. The matching names and contract to HSI make it fairly obvious, but in the end, it doesn't even matter it's never directly stated to be the case.
• If it is indeed true, then I see two scenarios: attackers are HSI mercs trying to blow up the toaster god, while defenders are the omnics corrupted by it OR the defenders are HSI, while the attackers are criminals or omnics trying to reactivate Anubis.

Volskaya Industries:

• Russian mech factory owned by Katya Volskaya, reactivated to produce forces to retaliate omnic forces during Second Toaster Crisis.
• Kinda clear and like in ToA; attackers are Russian forces trying to reactivate the factory, while the defenders are whatever crawled up in there during the interim. Alternatively, Russians defend the factory from an omnic assault.

Escort

Dorado:

• Mexican city. LumériCo tries to install power plants to bump the economy, give people jobs and all that, while Los Muertos oppose this because reasons.
• I don't think it's ever stated outright, but the attackers might escort Los Muertos van into LumériCo p-plant to start an overall mayhem, while the defenders are city police and the company's hired guns trying to stop the gang.

Route 66:

• By Overwatch standards, a likely vintage, Wild West-esque area that also seems to be the base of operations of the near-wiped out Deadlock Gang.
• If McCree's quotes are any indication, Deadlocks really want that payload. That kinda implied that the attackers are the Deadlock Gang trying to smuggle illegal kittens into a secure area, while the defenders, whoever they might be, don't want them to.

Watchpoint: Gibraltar:

• Thought-to-be abandoned Overwatch facility, now the area where Winston spends his time and conducts his scientific research. And hides from his enemies, maybe even law enforcement.
• That's easy one. Attackers escort Winston's satellite drone, while the defenders, likely Talon, try to stop him.

Hybrid

Hollywood:

• Of course, it's movie prop area, as you might expect from a Hollywood map.
• Attackers are likely mercenaries hired to escort Hal-Fred Glitchbot to his recording session. Defenders are probably some criminals that don't like omnics much.

King's Row:

• Obviously the relations between humans and omnics are pretty rotten there. Also, Tracer talks something about murdering people for a cheap something.
• Another easy one. Defenders are probably the police, while the attackers are Bri'ish rebels escorting the EMP device to nuke all the toasters in the area. Shame on you, Zenyattas rolled on attack there!

Numbani:

• The one place where humans and buckets of bolts omnics get along quite well. All that is actually pretty much irrelevant to the actual scenario, which we actually don't know.
• Well, we escort Doomfist's gauntlet. That's something, right? No idea who, no idea why, no idea where. Oh well.

Control

Ilios:

• Some nice, bright and sunny Greek city. Apparently some ancient relics are being unearthed there recently.
• So I guess both sides fight over the relics and/or excavation areas...?

Lijiang Tower:

• Some sort of shopping mall in the middle of the city. There's also some space research going on there, too, apparently.
• We I have absolutely no idea who is fighting over what and why.

Nepal:

• Monastery of the Shambali monks. Not much more to it, I mean, why would there.
• Someone tries to take control of the monastery, I believe...? I don't know, I imagine one of the sides would be Shambali, the other, I don't know, anti-omnic terrorists?

Conclusion

It's pretty apparent, that from the story point of view, Escort and Hybrid maps are the most fleshed out, while Control maps are severely' behind any other modes.
Maybe I'll get more info as time goes one, and once I get enough data on all those things, I'll start adding this information on map-specific pages.