I did a paper a few years back on the Falklands, looking very much at the Argentinian side, of which there is relatively little published.
It was quite clear the Vulcan's had nothing to do with the Mirage IIIs removal, it was (a) fears over countering Chile and (b) lack of infra to operate them.
Above all what came out was the total failure of thinking on the Argentinian side at any of the levels of war: Strategic, Operational or Tactical.
Strategic - completely underestimated the affront to the UK and that everyone would either turn a blind eye, or support them viz Argentina. Especially the Americans. Hadn't even considered having to plan for fighting for the Islands. They really expected to be able to waltz in and present a fait accompli and that would be the end of it, perhaps at worst with a UN force and transitional arrangement before they got complete control.
Operational - Air Force the junior service, not involved barely at all in the planning or initial Op, Army not a lot better. This was a Navy first, Army second, Air Force distant third, yet the actual fight was, and could only be, overwhelmingly by Air Force. Hence they had no plans, no infra, wrong aircraft and so on. Their logistics wasn't even a distant third in the planning and was abysmal, units literally almost starving. The actual defence was static, which reflected lack of vehicles and logistics but effectively sat and waited for the Brits to beat them. A key part of this was total failure to put an proper air component in the islands. Even a sqn of A4s with bomb stores would have changed it a lot, let alone Daggers there - again the Air Force hadn't been consulted or included, and so the planning to extend the runway (and they did have some kit) wasn't done/a priority. As we saw post war, it could have been done by them, and the Air Force knew very well the importance of that. Similarly they'd have expedited Exocet procurement if they'd known this was coming. This one failure probably doomed them as their air support was minimal, jets operating at end of their range with no margin for manoeuvring plus reduced bomb loads. Thus whilst the Brits never achieved Air Supremacy, they did achieve enough Air Superiority when and where they needed it.
Tactical - wrong troops, wrongly equipped with wrong logistics to support or change that. Some good outliers (tanking Etendard Exocet, countering Vulcan raids). They were right about low level attacks given how Sea Dart/Wolf dealt not too brilliantly with that, but they'd have been slaughtered at medium or higher. However they didn't join that up to arming their bombs! That is a sign of a very incompetent/non joined up engineering to aircrew talk if nothing else!
All in all, their Air Force and troop son the ground did a decent job, against horrifically bad Senior Leadership and planning. But of course that reflects that these were Leaders who sincerely thought the way to deal with difference was to chuck people out of aeroplanes, murder them generally and remove their children. So with absolute scum like that, you cant really expect inspired or even competent military planning, necessarily considering what if/problems you can't just murder away!
So, to get back to the point - 1983, not a huge change really, more Exocets, harder for Brits to generate task force (but not impossible), but given the road to war was scrap merchants and so on (to some extent, doing their own thing independent of the Junta), Britain may have started to take quiet steps to counter that and have something, anything in the pipeline to be there or reinforce it (ships sent south as before, additional troops), or even just some actual intelligence effort that would make the invasion less of a surprise.
Hmm this has ended up as a long response!