Yes, I believe frequency has been increased, given the cycle timing, as has been posted recently.
There are many parallel and intersecting processes handled by various functional teams within Admissions. After a board meeting reviewing admissibility, no one jumps up to speed to a terminal to start entering appointments to show up in portals within hours. Decisions must be made, nominations must be managed, yield statistics checked (appointments offered versus accepted), class-building objectives checked, appropriate senior leadership approvals obtained, final quality control checks performed, administrative tasks accomplished, elected officials informed, notifications organized for release, portals updated.
And, there are always more fully qualified candidates with noms than there are seats in the class.