Your version written in Java

  private static final int[] VALUES = range(0, 16).map(FizzBuzz::fizzbuzz).toArray();
  private static final int[] DELTAS = stream(VALUES).map(v -> v < 0? 0: 15).toArray();

  private static final VectorSpecies<Integer> SPECIES = IntVector.SPECIES_256;

  private static int fizzbuzz(int i) {
    return i % 15 == 0? FIZZ_BUZZ: i % 5 == 0? BUZZ: i % 3 == 0? FIZZ: i;
  }

  public static int[] simdFizzBuzz(int length) {
    var result = new int[length];

    var v1 = IntVector.fromArray(SPECIES, VALUES, 0);
    var v2 = IntVector.fromArray(SPECIES, VALUES, 8);
    var d1 = IntVector.fromArray(SPECIES, DELTAS, 0);
    var d2 = IntVector.fromArray(SPECIES, DELTAS, 8);

    var i = 0;
    var upperBound = length - length % 15;
    for(; i < upperBound; i += 15) {
      v1.intoArray(result, i);
      v2.intoArray(result, i + 8);
      v1 = v1.add(d1);
      v2 = v2.add(d2);
    }
    for(; i < length; i++) {
      result[i] = fizzbuzz(i);
    }
    return result;
  }

quite cool indeed