1)The number of Linked mobs.
The link system as a whole was already commented on that they'll be adjusting this in due time since a lot of patch 1.18 - 1.20 were foundation patches and adjustments would always come later.

3)The respawn reset timers.
I believe this was done this way purely because people complained about low respawn timers (and complained that NMs shouldn't have long respawn timers...) so I think is this likely a permanent change.

Though the party situation in general they did say will be further adjusted.