Gotta pay to play folks. No reason to expect the most desirable stuff to come free with subscription. Remember, it's Ferengi Economics. If people want it, charge for it... if they aren't complaining about the price, charge more.
I think the Ambassador class is cool but don't know exactly where it would fit in the grand scheme of things. Obviously its smaller and less powerful than the Galaxy so it would have to be a CM level ship if any degree of canon was to be stuck to at all.
Perhaps this (and a few variants) would be a good replacement for those awkward 4 nacelled Cruisers.