Simple MVP Name-Finder
The UpdateNames event should be TeamChanged or something, so that it tells the presenter what happened on the view, as opposed to what the presenter should be doing; "update names" sounds more like a method name than an event, too.

The presenter shouldn't know about any form controls: the view knows about the model - there's no need to round-trip to the presenter to update the list of names, IMO that's pure presentation logic that should remain encapsulated in the view.

The IsValid logic could be used to keep the OK button disabled until the model is in a valid state; that way you wouldn't need that MsgBox, as the user wouldn't even be able to attempt to submit incomplete/invalid data.