The ICAO PANS for reduced runway separation minima were amended in March 2005. I think you'll find that the 'land after' procedure reflected the earlier PANS.
If I am recalling the amendment to PANS-ATM correctly it would appear that the UK and Italian procedures have not been reviewed for consistency with ICAO procedures and updated where necessary.
bob, certainly in my day, 'land after' was commonly referred to by controllers as an instruction in order to distinguish it from a clearance. I don't think there was ever an intention or implication that any of the options available to a pilot making an approach were different.