I don't know really, but how can it be a separate hechsher if it's the same one?
Anyway, the benei Torah in ey (Israelis) have never eaten OU. This is primarily due to the fact that the orthodox Union is a modern orthodox hashgacha and organization. Combined with the fact that they have a whole bunch of mainstream solid other options for kashrus.
I guess that would explain why this south African guy who came to visit israel is busy brain washing me that there are two different OU's and not the same reliable.
And he even agrees he would not eat the ou as he relies on the one hechsher they have in south Africa, while here is israel he will eat only the fachnachta brands.
I do see that nestle makes the cheerios and even says, cereal partners worldwide nestle and general mills.