Well, actually, they're held by Erik in his MPEx account.
This is a very important point. If X thinks they're worth 70 and buys, nothing has changed. If X thinks they're not worth 70 he shouldn't buy. If he buys anyway, for whatever reason, he has no right to complain. The entire "greater fool" approach to investing isn't too well regarded on MPEx, and I guess not too likely to succeed on the long term anywhere.
Actually the gap was closed already. Those in the best position to pick up a bargain are first those with bids in, as the sale happens, and second those with cash available on the exchange. There's (and there should be) a benefit from keeping BTC available so one doesn't have to wait for deposits to clear.
Complete speculation here but perhaps another reason Erik is willing to sell these shares and take the bitcoin (and do what he wants with them), is that he thinks it is somehow legally less risky to do this than to convert his SDICE earnings into USD (fiat). If SDICE earnings are only kept in bitcoins there is maybe some legal grey area with US gambling laws but if he converted his dividends into USD there could be some issue.
I think he just wanted to give more people a chance to be shareholders.