From what I understand, a map wipe is required, given the massive overhaul to terrain in the update.
BP wipes are usually never required unless there’s some sort of overhaul to the BP system, but that rarely happens. As such, BPs stay for as long as server owners/admins want them to stay.
in theory, map wipes should only happen once a month now, but for high population servers, that’s pretty much impossible given the ~150k collider limit in the game currently. Most high pop servers, like Rustafied, reach that in less than a week, so in order to keep the server from performing like shit, they have to wipe.
Once Unity decides to upgrade PhysX to 3.4 from 3.3 (probably won’t happen anytime soon), or FP finds a way to either increase the entity limit or decrease entities over time (like decay in Legacy), this shouldn’t be much of an issue anymore.