The school has a strict occupancy limit (due to the neighbors, basically) so if they need to do reductinos, it tends to be in lower school. 4th isnt' a typical entry year, so that's a good place to do it.
Here's the website of the neighbors in opposition to any expansion:
https://noholtonexpansion.com/
In particular, I find these points of objection the most amusing:
"Make Granger House a permanent office, instead of reverting to residential use" -- this building is way internal in the campus and won't disrupt neighbors at all. Actually this one has already been approved via a separate request, for that reason.
"Holton-Arms would not be required to monitor or limit what types of events take place." -- Holton wants to rent their fields out during the weekend, for example for lacross tournaments. Their brother school (Landon) already does this. Do the neighbors think Holton plans to rent out the fields for some type of wild Gatsby-like parties.. on a turf field?