Nothing Orders Memory

Both atomics start at 0.

std::atomic<int> x{0}, y{0};

// thread A
x.store(1, std::memory_order_relaxed);
y.store(1, std::memory_order_relaxed);

// thread B
int a = y.load(std::memory_order_relaxed);   // reads 1
int b = x.load(std::memory_order_relaxed);   // reads ?

Thread B observes a == 1. Is b == 0 a legal outcome under the C++ memory model?