Nothing is deleted.
Your training, your history and your watch sync all keep working. Your coach rests, and picks up where you left off whenever you come back.
Once you have paid for three months, editing your own calendar stays yours for good — subscription or not. That is written into the Terms (§6), not only here.
Coming back later does not mean starting again. Your coach reads the same history it always did.
Asking about a refund rather than a pause? That is a separate question with its own rules — the Refund policy is the authority, and it reproduces the two clauses of the Terms that govern it.
Where this lives in the app: Membership