I disagree a little. It does mean something. Clearly in this and other cases the producer has decided that for one reason or another they are going to market a higher tier than their usual wine. If this is simply just putting a different label on the same bottle then I would be very disappointed even from a store like Tesco - they aren’t as good as TWS but even they would be pretty unhappy with sharp practice like this. That leaves some degree of tiering of wine. It may be a small or barely perceptible difference but surely there must be something going on.
Nothing wrong with that necessarily. Cono Sur produce a hell of a lot of wine for supermarkets but also make Ocio, which Toby Morhall has in the past called Chile’s best Pinot Noir!
If you like the original then maybe it is. You’re on TWS community, so if you wanted to go on some esoteric voyage of Malbec you would probably be picking a mixed case from the list and ordering them in. But you were in Tesco so this was probably a more spur of the moment purchase and wondering about the tiers for an everyday drinker - I therefore say it probably is worth it!