No, they're not the same; it is clearer if you use more values; here a is just a dummy to initialize - the important bit is how the usage with c and d work differently; with b = ref c; we update the reference that b points to to c, so if we look at c afterwards: it is different; with b = d; we update the value of the thing that b points at, so it behaves very differently - b still points at the location of variable c.
int a = 0;
ref int b = ref a;
int c = 1, d = 2;
b = ref c;
b = 42;
System.Console.WriteLine(c); // 42
System.Console.WriteLine(d); // 2
b = d;
b = 64;
System.Console.WriteLine(c); // 64
System.Console.WriteLine(d); // 2
If we compare in terms of pointers, and say that b was an int* pointer:
b = ref a;isb = &ab = ais*b = a
Yep, I realize my question was based on a misunderstanding, as both variables in my question continue to refer to the same actual storage. Assigning the value of
atobjust tries to update the referenced storage with its own value, which does nothing.