Based on the timing, I'd hope that the latter is the case, although I'm sure Amtrak doesn't mind the extra revenue either. It would only make sense for it to get the first crop of the new cars. The other eastern LD trains are already running at the level that they should be. They have the needed sleepers, and the heritage diners, while old, are better than nothing (or a diner-lite). I'd think that Amtrak would want to get the Cardinal, which is the most under-equipped LD train in the country, up to where it should be first, before trying to supplement already adequate trains.
If this does turn out to be the case, Amtrak will have impressed me twice in as many weeks. They will have finally gotten the message that the Cardinal is a good route, with a lot of potential, that can be made much better.
Here's the Cardinal's current consist:
Power, H. baggage, sleeper, diner-lite, coach, coach, coach
Here's what it needs to be:
Power, bag-dorm, sleeper, sleeper (maybe), diner, cafe, coach, coach, coach.
At the very least, it needs to get bag-dorms ASAP.
Once enough equipment is in place, they can construct a third consist and make the train daily, but I don't expect that to happen until late 2015 or 2016.