While it is not unprecedented for underwriters to allow for an early expiration of the lockup, it is rare, and in any event I haven't seen anything about it. Since the main purpose of the lockup is to prevent insiders from dumping shares and hurting the original IPO buyers, it is possible that underwriters would allow some selling now, but still unlikely unless of course there is an announcement.
In any event, underwriters are not at risk. The only risk they have is if insiders bail and the original investors get hurt. But since they bought in at $21 (and most have likely bailed by now) and the stock has run up like it has, any deterioration in the current price will not affect their ability to place shares in the future. Afterall, if someone gives you a chance to buy a stock that runs up 200% in 6 weeks, you'll buy from them the next time (and once again bail to leave the retail ninnes holding the bag).