> We have zero idea on whether the manager's phone was there.

But the manager can be sure she didn't receive an acknowledgement from OP to confirm she had received the policy. Which is kinda important.
Before covid I was stuck at home in sick leave with orders to come back to work at X day... but in the mean time lockdown happened.

Absolutely everybody assumed that everybody knew the procedure and forgot that people on sick leave have no way to reach the company-wide comms.
THANK GOD I had my boss's personal phone number to call directly against the usual policy.