It's a form of prophecy-aversion that's pretty orthogonal to the various forms of destroying Harry. The mechanisms of prophecy are still an unknown for Voldemort, and it seems potentially consistent with how magic works that all attempts to neutralize Harry are doomed to fail but redeeming him with friendship can work.

...or he's setting up his next chess match, either as an explicit goal or as a subconscious desire influencing his prophecy-aversion plans.