Playing devil's advocate (or devil's PR) a bit: I think you guys need to decide if you haven't already, or make clearer if you have, what the actual purpose of the bundle is from a player's perspective.
What I mean by that is that I think it's clear what you guys all hope to get out of it: a concrete outcome to drive the first stage of the incubator, a bit of cross-promotion, maybe a mention on a couple of gaming sites, bring in some players who haven't tried roguelikes before and so on. But what isn't so obvious at least to me is what exactly is in it for the prospective player. What are the key selling points? What's the 'story'? Why should I, Mr. John Q. Videogamesplayer, give a crap?
The humble bundle etc. offer the purchaser a chance to buy a load of games a lot cheaper than they usually would (or a lot more expensively, if they choose to be very generous) and in doing so try out some games that they might not have done otherwise.
Obviously, that doesn't quite work here because (presumably) all of these games would be released for free anyway. So there's not a lot of financial incentive to waste bandwidth downloading them as a bundle when you could just grab the one(s) that you might be interested in individually and ignore the others - like you can with any other freeware game. You could emphasise the 'for charity' aspect of it but it seems like that's entirely optional anyway and something of an afterthought - the current website doesn't put a whole lot of emphasis on it. Of course the danger with really pushing that aspect is that it might seem a little disingenuous to people familiar with the origins of the bundle, but what the hell - I won't tell anyone if you won't.
Alternative spin, and I guess the one you're probably going for, is quality: i.e. these games have been through a rigorous and intensive development 'boot camp' and are the best of the best of the bestiest, quality 100% guaranteed. Of course in this case the games need to actually be really really good (as I'm sure they are), but then this is still really more of an outcome of the incubator itself, and the bundle is fairly irrelevant - the incubator is the focus of that story. Where the bundle might gain some ground however is if it were selective - if it represented the 'best' n games to have been developed in the incubator as selected by peer review (or public vote, whatever). It seems like you don't really have the number of games to do that, however, and so should delay. And of course it's maybe not the strongest pitch in any case - most people won't know you from Adam (or your games from ADOM) and have no idea what any guarantees of quality you might make would be worth - while those of us that do will probably play the games anyway, bundle or no.
Alternative alternative spin would be something more akin to something like the 7DRLs - that creating these games was a specific challenge/accomplishment that took place under certain conditions and restrictions and the bundle is the result of that incubator 'experiment'. In which case you shouldn't change the release date because what's on trial is not just the games themselves but also the process/environment that they were created in. This doesn't really present any benefit to the players but it's still something that might pique their interest and get them to try out the games.
Anyway, you get the idea - I think you need to focus in on what exactly you want the bundle to achieve and then from that make the decision about what should go into it and when it should be released. At the moment it seems a little like you're doing a bundle just because indie bundles are like, so totally in this season and I don't think that's a good enough reason on its own.
