doubtful. if the blackout doesn't stay, the issue will be forgotten about. The majority of users won't see a difference for awhile, probably until a bit after Reddit goes public and makes the API switch. and by then investors will have pulled money out, moderators won't be able to moderate, and Reddit will die slowly (or quickly, depending on spam volume after the switch).
An IPO is the least of his concerns right now. It is clear they are on the verge of bankruptcy and are panicking, desperately trying to find some source of revenue to keep the lights on. In the past they would find more investors, but investors have had enough.