You’re correct in that future privacy settings will not be configured, however you are guaranteed to receive future privacy-related features and security updates provided by Mozilla immediately as they are released. On the other hand, Librewolf guarantees that all updates will have their privacy settings configured by default by Librewolf developers, however you are not guaranteed upstream features and security updates in a timely manner… 1-3 days is not usually significant, although it can be, and it’s never guaranteed to be that short of a turnaround. IIRC Librewolf fell behind on updates for longer than that at one point.
It is definitely a trade-off either way you go, I think our preference is just for the former over the latter.