Short answer;
That’s normal/expected behaviour - all workouts should be available to you, to do as you want (in whatever order). Though I agree the “do by Saturday evening” text is superfluous, as it’ll still be there when you do a workout from the plan next week.
Slightly meandering answer;
Workout plans used to have a prescribed order that workouts could be completed (with enforced breaks between them); this was somewhat relaxed in March 2022 [link to notes] where each week’s workouts would be unlocked on the Monday, with no restrictions on what order that week’s workouts were completed in.
The May 2022 update [link to notes] removed the week-by-week restriction of the plan, basically giving everyone free reign to pick and choose from a workout plan (over however many weeks it’ll take for them to complete it all).