As far as I can tell, this is due to the old equipment at Scottish! Down at London they have the capability to confirm the squawk on departure as Validated but under the rules, here in Scotland, we have to follow MATS Part1 and validate and verify a squawk on initial contact.
More pilots appear to be coming on saying callsign, passing level, cleared level and squawk with ident. This just leaves us to say "No Speed and up you go". Sounds like a great plan to me.