I'm kind of sitting on the fence on this one. On one hand, I love the old default maps that Soldat started out with, when the dominant colors were red and green and the maps had a single unshaded/partially shaded texture. However, I am also an admirer of newer maps that have a lot more definition. Maps by VTT and Kamikazeduck are probably my most favorite. Excellent visual design, layout and varieties of themes.
I think like p0ppin said, a poll would be an excellent idea. From what I've gathered from the community for the last 5 years at least is that, both simplistic 'old' defaultish and well made - with lots of visuals maps are favored. Demonic started the Mapmine long ago and filled it with only the best and amazing maps (haven't checked it lately to see if it's still updated). So basically, the community has supported both simple and complex styles. It's only fair then that the game should have some of both, IMO.
And, really it doesn't matter which maps come default with Soldat. They could ALL suck. It's up to the server owner, what maps they want to support. So if for SCTFL as well or other competitions - the majority of players favor old versions or old maps, then the servers can host just those old maps.