As DM I'd never tell them out-of-character what the next adventure was going to be* unless they had some way in-character of finding out and then did so. In general terms, if asked ahead of time I might say there'll be a variety of different adventure types as the campaign goes along, but that's about it.Setting aside how a group of wizards would perform in a dungeon crawl (amazing, I was told recently, just because of unseen servant alone), the question I would have here is why is the group creating a gang of wizards when the DM is running a dungeon crawl? Is this group talking to each other at all? Does that make the DM adversarial or the group just uncommunicative? If I as DM say I'm presenting content X and the player agree, then show up with characters that aren't very good in content X, that's not on me.
* - the exception being if I'm planning on running a module that some players might have already been through or DMed, I'll ask if they have; in these cases I have to trust the players not to tweak the party makeup due to this meta-knowledge. They're usually pretty good about it.