Hi!
Yes it can, but I would not recommend changing it.
If you need to change it, I suggest you send us your questions and why you need to change it for assistance.
//query the priority of the mac-address learning :
huawei#display mac-address learning priority
UNI MAC address learning priority : 1
NNI MAC address learning priority : 2
//change the mac-address learning priority :
huawei(config)#mac-address learning priority
{ nni<K>|uni<K> }:uni
{ pri<U><0,3> }:1
Command:
mac-address learning priority uni 1