The application could be well behaved and set the path to /snap/bin/my-snap-command and have it launched with proper confinement. The problem is that it could just as easily specify some other path: the user would have to trust the snap to behave rather than the sandbox ensuring that the snap can’t misbehave.
With that said, we do grant classic confinement to snaps where it makes sense. That provides a similar level of access to the system, so I’m not saying your request should be denied outright. Just that it should probably be judged by this higher standard.