Did God plan the "Fall"?
It is hard to see your connection with the Sabbath in this question, but this question does touch upon an important dilemma that perplexes the modern mind: Was the Fall of man into sin "planned" by God? And what part does "predestination" play in this...in conjunction with "free will"?
Illustration
An illustration drawn from what we all are familiar with may serve to answer this tricky question: schoolroom education!
A professor (or teacher) is in total control of the classroom. He sets up the schedule...chooses the textbook...writes the syllabus...grades the exams.
When a student enters the scene, the professor is told that if he\she follows the syllabus, earnestly studies the text, and passes the exam, he/she will be given a passing grade.
If, however, a student---the teacher informs---does not show up to class, is lethargetic in studying, and does not prepare for the exam, he/she will fail the class.
Now, the student is exercising "free will". He is not predestined to pass/fail. AND the professor has exercised complete Sovereignty all the while. The professor did not "plan" any student to fail. He did not "Plan the Fall".
Continuing the Illustration
The professor informs the student that "if" he/she fails the test, a make-up test will be given...and a perfect Mentor will aid the student in learning the class material! A rescue is preplanned by the compassionate professor, so there is no excuse for anyone to fail.
Sovereign Creator
Yes, God made fallible man, AND He made a rescue plan if/when mankind failed to obey the rules of life laid out by the Creator. He did not "plan the fall" but He made provision for its redemption.
The many rituals, sabbaths, sacrifices, holy days observed in the Old Testament (Tanach) were signs given by God to remind everyone "that help was on the way"! They pointed to the Mentor, the Savior, who would make possible that no one should ever have excuse to fail on Judgment Day!
So, God did not plan the fall, but He did plan the Rescue for those who did fall! The "shadows" find fulfilment in this ultimate Rescue; they did their job. Now we live in the sunshine of the Light of the world.
Sabbath
The symbolism of the "Sabbath" is found in the Resting of God from the works of Creation, not in the future "Fall of man into sin" later in the Garden of Eden. And it is interpreted in the book of Hebrews for us:
For we who have believed do enter into rest, as He said, "As I have sworn in my wrath, if they shall enter into My rest"---although the works were finished from the foundation of the world.
For He spoke in a certain place of the seventh day on this wise, "And God did rest the seventh day from all His works." (Hebrews 4:3-4
The writer explained that those who follow Christ have symbolically entered into the same kind of rest from trying to work for their Salvation:
There remains therefore a rest to the people of God. For he that is entered into His rest, he also has ceased from his own works, as God did from His.
Let us labor therefore to enter into that rest, lest any man fall after the same example of unbelief [as the Israelites committed]. (Hebrews 4:9-11)
God's original plan was for all men to rest with Him in the Garden of Earth and enjoy Creation...AND His effulgent holy Presence, walking with Him in the cool of the evening!