In Mathematica 11.1 you can convert your network only into a ClassifierFunction. I expect that converting into a PredictorFunction will be added in the next releases.
net = NetChain[
{100, 2, SoftmaxLayer[]},
"Input" -> 100,
"Output" -> NetDecoder[{"Class", {0, 1}}]
]
SeedRandom[0];
X = RandomReal[{-1, 1}, {1000, 100}];
Y = RandomInteger[1, 1000];
net = NetTrain[net, X -> Y, MaxTrainingRounds -> 1]
c = Classify[net]
