I'm a bit worried about this. Any shoulder related injury is reason for concern. And even if it won't have any long term consequences, it's bound to interfere with her preperation for the AO. Everyone else is having what for them is the ideal preperation while Maria will have no matches under her belt and will only be able to train at less than a 100%. Not a good way to start the year by any means.
Let's hope for a soft draw in the first couple of rounds at the AO so that she'll get some time to work herself into the tournament.