This one is simple: yes. Unless there was an unprecedented lawsuit that resulted in EA Sports losing the rights to the likeness of the organization and their players, you will be able to play with the Los Angeles Chargers in Madden NFL 18 complete with their uniforms (if they make changes), stadium, and tendency to see players wind up on injured reserve.
A report came out Thursday morning from Vincent Bonsignore of the Los Angeles Daily News that the Chargers may consider a rebrand; it likely wouldn't be immediate, but a change could happen in the next few years when the Chargers adopt new uniforms and a new logo.
But, I wouldn't be worried about that just yet. As of right now, previous Chargers uniforms -- including the throwback blue and gold ones -- are most likely to be in the game.
The reason why I say most likely is because that comes down to rights and likeness issues, but given that Madden NFL 17 kept all of the Rams' throwbacks after moving to Los Angeles following last season, I wouldn't be worried.
Speaking of the Rams...