Using auto with initializer list

I have question regarding interaction between auto and initializer list. Example code:

#include <iostream>

int main()
{
auto a{ 1 };
auto b = { 1 };
auto c = 1;

std::cout << typeid(a).name() << std::endl;
std::cout << typeid(b).name() << std::endl;
std::cout << typeid(c).name() << std::endl;

return 0;
}

Gives output:

int
class std::initializer_list<int>
int

Which is kind of confusing. I'm posting this question as a followup to this. What should happen? I've did some research and it seems that auto c = 1; is illegal now, and it seems that it works because compilers allow this as a backwards compatibility patch. Does this apply also to auto a{1}?