As we wrap up the מאמר, the רבי uncovers a tremendous depth in the quality of יציאת מצרים, which explains why we compare the final גאולה to it, and why we will mention it even after the final גאולה:
In our daily service of Hashem, יציאת מצרים represents "אתכפיא", when we can only subdue evil, either by ignoring it or by fighting it. As opposed to the final גאולה, which represents "אתהפכא", when we transform evil.
Although transformation is obviously greater, there is a quality in fighting the evil - specifically in that there is evil to be fought. Hashem gives us temptations specifically to fight them, Hashem gives us challenges specifically to overcome them. When we do, we fulfill the deepest purpose of our creation, bringing Hashem tremendous pleasure!
When משיח comes, we will not have any evil to fight; we will lack that עבודה of אתכפיא - and that is exactly why we will still mention יציאת מצרים!
Struggles don't get in the way of your freedom; they are the way to your freedom!