The trains to Munich aren't exactly a half hour apart. There are two an hour, but not spaced evenly. If you are coming in on the TGV and leaving on the ICE, the next train to Munich (probably an IC or EC, not an ICE) is about 45 minutes after the ICE.
If you do have a non-transferable Savings Fare ticket, and you miss your connection, go to the ticket counter in the Bahnhof and show him your ticket. If you did miss the connection because the TGV arrived late (not because you walked too slow), he'll change the ticket to the next available train, either the EC 45 minutes later or, since your original ticket was for the ICE, maybe the ICE an hour later.
Fortunately, since this is the last stop for the TGV, you won't have to fight through a crowd of people trying to get on the train while you are getting off.