There were no other reshoots before the ones this last month. They've been rescheduled and kicked down the road a few times but the only actual reshoots are the ones this past month and, based on the first AD stuff, seem to be the only ones they're doing. And, like previous reports indicated, they seem to be mostly involving action sequences.
I genuinely have no possible idea what CGI you are referring to except like the Space Needle in the background. The shot of them fighting is not CGI except for the swords being pulled out
World of Reel is not reliable for exclusive information. They make shit up for clicks constantly, the rest they literally just copy and paste from other outlets. There is absolutely no way this costs more than the Avengers films.
The announcements have always been made by Sony but they've had Spider-Man at SDCC before so working something out with them isn't impossible. But they also definitely can't do it at D23 so if it's coming anywhere SDCC is it.