Even when volunteer stations are transitioned to either MOSCAD or the data system for station alerting, there will still need to be a pager system maintained for volunteers and staff officers. They'll keep 46.46 up as long as it will work, since they've dumped so much money into replacing pagers with Minitor 4 and Minitor 5 models. When it all finally reaches the end of it's life cycle, I anticipate you'll see alphanumeric paging for volunteers and staff officers.
For now, it's a safe bet to purchase a 46.46mhz pager, but shouldn't your company issue you one?