Training plans: Why the delay in releasing each session

I’ve signed up for the build me up training plan on Zwift, but it delays releasing each session, e.g., this weeks plan had 4 sessions, but two of them were released today, giving me just two days to complete them both. There are 7 days in a week, why are they not released on a Monday so I can spread them out over the week according to my schedule, not that which Zwift determines.

I’m away this weekend, which means I’m going to fail the final two sessions. I could have done these in the week but they’ve only just unlocked.

Does anyone know what happens if I miss a session? Can I catch it up?