Well, yes, the S-2 should have an idea of what we're facing, but I'd prefer to leave that to us human players. The situation briefing for each scenario gives enough (sometimes more than enough) enemy OOB information.
Besides, the intel boys have been known to be wrong, or just late with updates.
If the "enemy kills" listing doesn't show 125mm AT guns until I kill one, then I as the player have to worry, "The briefing said there were enemy AT guns in the area, but I haven't seen any yet. Are those guns 100mm or 125mm, or was intel wrong, or is something else here in place of the AT guns?"