Uh. In a word, no.
You can be interested in any program. You can state that you are interested in said program. However, up until the time that you actually submit an application to that school, *and the application is submitted through a linkage agreement* (which works a bit like early decision), you are not obligated to attend that school.
Random metaphor: saying 'I want to be an astronaut!' when you're a kid doesn't mean you are obligated to fly to the moon when you grow up. You're not obligated to go to space until you are strapped into a seat on the shuttle.
Saying you are interested in linking to a med school doesn't mean you you have to link. Stating an interest is an important step in gathering enough information to make a decision about where you want to apply. There are no obligations *until you submit that application through the early decision/linkage system*. Anything and everything up until that point is free game.