The LIF rebalancing feature is indeed deprecated. It was only used by a very (very) small number of customers, and it only worked for NFSv3 - not CIFS, not NFSv4 - It was disabled if any of those protocols were enabled on a LIF.
Any traffic to a LIF on a different node to the aggregate hosting the volume would result in indirect access, and thus cluster interconnect traffic, and thus, in the end, CPU and disk load on the source node anyway, so it didn't give much of a benefit.
Depending on your data layout and use-case, using flexgroup scale-out volumes across multiple nodes may be a better solution, along with LACP for interface distribution on those nodes