Yes it does. The Dunkirk campaign was a retreat, not an attack.
And that changes.. what, exactly?
The retreat at Dunkirk was done under fire, just as a landing in Britain would have been. Further, assuming that the Germans had air superiority, any real resistance on the beaches that would prevent a landing would be bombed out of existence.
Unlike France in 1944, Britain did not have a giant wall of machine-guns and minefields on their shores. A landing (With proper air cover) would have been a cakewalk compared to any other landing during the war.
Are you forgetting that Germany's air force was the most depleted combat arm after the French campaign? The Dutch alone shot down a quarter of it.
It was anyones game at the start as Britain still had a decent quantity of Airplanes at that point, they were still able to match the Germans, and they had the advantage of fighting in their airzone.
Which is why the invasion
did not happen. I am working under the assumption that the one thing that would allow the invasion to happen had occurred. Without air superiority, there is no invasion, because it would have been suicide, especially with a lack of dedicated landing craft.