So just to clarify, this clause is valid for season long loan that if in January he wishes to return to NUFC he may do so? Can't say I have ever heard of this.
Otherwise it's straight bollocks because he is off contract in the summer anyhow, but then again we know once the season long loan expires he WILL definitely return albeit off contract and it's up to NUFC whether or not they release him on a free or not.