There are so many things wrong with this theory I don't even know where to start.

1. If the third used the same technique that the fourth did on Oro's summons, he knows that the technique causes death. Thus he knows that the fourth is dead. But disregarding this, let's assume that the fourth is alive.

2. Oro did not leave the village before Kyuubi's attack, I'm pretty sure of that. It makes no sense that the 4th would only trust Oro if he had the power of sharingan. Does sharingan automatically make the person who has it truthful or trustworthy? I think not.

3. From events in the manga, we see that Sasuke has really cut his ties with the village. He wants power and was willing to go evil to get it. There is no way that Kabuto would help Sasuke against Oro, he is completely dedicated to Oro. This has been shown many times.

4. No one called an akatsuki member "Yondaime". This guy is probably referring to the faked manga page that shows the fourth as a member of akatsuki.

There are many other problems, but in short, this theory is a steaming pile IMO.