It seems he aggressively discarded pretty much everything O Sensei talked about and just taught the outer form and described it with his own concepts. He didn't know and didn't care what Ueshiba was talking about, except that he considered it pointless.
In the 25 years I spent as Sensei Maruyama's student I can assure you that the idea that Tohei Sensei taught only the outer form of Aikido is incorrect. All of the teaching (Ki development and waza) was directed at fostering a strong mind/body connection, first within oneself and then with a partner. The push testing employed by O Sensei was carried over and employed with regularity. After leaving the Ki Society Maruyama Sensei continued to stress that for Aikido to be effective students had to develop power and strength that didn't rely on muscle. This power is generated from what he termed "correct feeling".