I don't think Michael Saylor has any hidden information that is motivating him to keep on buying Bitcoin regardless of the price. He just has the conviction that Bitcoin is the best investment for him. He believe that the price will keep appreciating more than the cost he is paying to purchase .Some people are fascinated about gold or real estate and they keep acquiring it no matter how high the price goes.
Based on my observation I don't think Microstrategy has any current plan to stop acquiring more Bitcoin. Maybe they will stop when Saylor changes his ideology about Bitcoin or if he dies.
Since most of Microstrategy purchase is in public domain, I think their main purpose for investing is profit. Bitcoin is also becoming a symbol of economic power since we are gradually entering a phase were the it will be used as a reserve currency.