So that looks like the church where Mike is placing the figures. The building with the tower to the left in the square is the library which is shown to be barricaded off by the military. This area around the library is probably where the kids, Mike, Will and Joyce encounter Vecna at the end of Vol. 1 and Vecna is shown to be in the library in the upside at the beginning of the trailer.
The figures look like a paladin (shield, sword, and helmet) which I'm assuming is Mike. Will's painting in Season 4 showed Mike's paladin with a shield and we would expect them to continue that imagery. The other figure is tricky. It looks like a blue cloak/hood. Now, I want to assume that is Will--because of Churchgate, the fact that Will and Mike seem to be a pair, and because I want it it to be true because I love Mike and Will (not even for just byler reasons, I just like their dynamic). But the weird thing is that a hood just doesn't match up with the images we have of Will the Wise. Will the Wise pretty consistently has a pointed wizard's hat--in the painting in Season 4, will's costume in Season 3, Will's drawing in Season 2, and the D&D figure that Eleven picks up in Season 1 all have a pointed (often purple) wizard hat and staff. So it would be a little weird if this was Will based on that.
So who is it? Looking at the other figures on the table next to the map, we see a van that looks like the radio van, a green car (military vehicle?), another figure with a sword or spear (maybe this is Lucas's figure who also had a sword in Will's painting) a figure in black with its arms out (some kind of rogue?, Dustin's bard?), a gray piece (maybe a monster figure), a figure in gray robes with maybe a pointed hat and what could be a staff (this might unfortunately be Will's mini), a figure with an orange cloak (this is definitely Holly's new D&D character based on the pictures of her in her cloak).
If the paladin is Mike, then Will makes the most sense to me. I don't think it would be Mike and anyone else based on who he seems to be teamed up with this season (Joyce, Robin, Holly, and some other kids). And I don't think either figure is Dustin or Lucas. Dustin goes off with the teens and Lucas is seemingly alone or with Max (and Max wouldn't be able to get to the church at this point). The location of the church in relation to the barricade might explain why Will and Mike end up in the area around the library ultimately.
In terms of people who are paired up, who could it be? The hooded figure could represent El and the paladin could represent Hopper? El's training look this season with the bandana is giving undercover (cloaked) vibes. Hopper meanwhile is bodyguarded up with El this season (and we have seen him fight with a sword before so a sword and shield makes sense to represent him). Could Mike be describing some plan in which El and Hopper might be trying to get to Vecna (whose base this season is probably the library) via the Church? But why would he be laying out what Hopper and El are doing for Lucas, and Dustin, and Will? Wouldn't it make more sense for him to be making a plan in relation to themselves?
I don't know and I definitely could have gotten some details wrong here but I can't wait for this season. I am intrigued by the fact that one figure obviously seems to point at Mike but the other is more vague. Also I am interested in knowing the significance of the Church. It hasn't been a relevant location really yet, not like the library (where Will ended up intubated season 1 and where the nexus of the portal cracks into hawkins appeared in season 4). The church did have that hate message at the end of last season which ties to hellfire club, etc. and of course knowing Will's sexuality it feels like a thematically juicy place for Vecna to prey on Will's "otherness" but I'm not sure about that. Why would Mike be planning to go there if that is his figure?
