No it is not noemal for alloy.
Powder coating was invented specifically to paint aluminium.
The part was not properly cleaned prior to coating.
It can not be repaired and will not last very long as water will attack the inside of those pinholes then lift the coating.
This was obviously done by a discount paint shop who used to wrong powder.
The coating actually chemically combines wit the oxide on the surface and then when it gets baked it fuses together.
