The rule for allowing combined schools is very specific and unlikely to happen now. Bland/Rocky Gap, prior to consolidation, were the last schools to do this. No schools currently meet the criteria to combine. It's doubtful we'll ever see another combined school unless the rule is changed. I'd personally like to see it changed so that kids in Highland, Chincoteague, and Rappahanock County can participate and compete in sports their schools are unable (or unwilling) to field, even if they have to cross school division lines to do so. I realize the imposition this would be for neighboring school divisions, though. I suppose allowing private schools to compete with public schools is the current way around this.
Like Goat said, it's simple math. If two small schools consolidate and still have 1A enrollment, they should remain 1A. Why make them play against much larger schools just because they used to be separate teams? The OP didn't call out any schools, but the only recently consolidated schools in 1A are Eastside and Twin Valley. While I don't follow many sports outside of football, I doubt either of these programs are dominating the other 1A schools in their area.