For example (even though this would never happen):

To TOR: A. Georgiev
To NYR: F. Andersen (conditional)

If Toronto makes it to the ECF or further with Georgiev, then Andersen goes to New York. If not, Georgiev and Andersen stay with Toronto.

No, but technically NYR could trade Georgiev for future considerations and have a handshake agreement to get Andersen if Toronto makes the ECF. And if they do, TOR trades Andersen to NYR for future considerations. Or, what used to happen, is that Andersen could be the future considerations, but future considerations actually being something hasn’t happened in a long time.

The CBA's literature regarding trades deal with NTCs, NMCs, Retained Salary and logistics. There isn't anything in the CBA which forbids a team for doing this type of trade, however, I think it would be a legal issue if it actually were to occur.