John, first is there any compelling reason why you must be on the 7:49am train? Seems the 6:41am train would work just as well. Since you can begin booking in March 2014, this is plenty of time to see precisely when the train will depart. No ambiguity at that point. Mystery over. You are worrying way too early.
Second, DB Bahn receives their schedules from the different trains systems around Europe. They do the best job of placing them online. However, for nailing down the most accurate schedule for a particular country, you really need to look at the train system for that particular country. In this case, it's the French SNCF site. http://en.voyages-sncf.com/en/ If you looking before mid-June, you can see the trains but you can't book them until you are within 90 days. If you need to see the train schedule beyond mid-June, you may be out of luck as you will have to wait until SNCF refreshes their schedules. DB Bahn cannot help you there.
Last, when using http://en.voyages-sncf.com/en/, do not select USA as your Ticket Collection Country. If you do use USA, SNCF will try and switch you to RailEurope which you do not want. Instead, select Great Britain, France or any other country listed to stay on the SNCF website.