standby and upgrade policies

Looking at 885 status right now and it is an interesting picture:


- United Global First®: Available | United BusinessFirst®: Available | United Economy: Full |

- United Global First®: 12 | Booked: 8 | Checked In: 10 (two people are shown to cleared upgrade)
- There are 5 people in GF upgrade list

- United BusinessFirst®: 52 | Booked: 34 | Checked In: 32
- There are 5 people in the BF upgrade list

- there are 6 people in Standby list

So clearly BF has more empty seats then people in the upgrade list (5), at the same time there are 6 people in the standby list and Y is fully booked.

Now, let's imagine that there are 15 pax (instead of current 5) that all of those have tickets in Y. What would be the policy to accommodate standby passengers?

- will already checked in Y upgraded into C and standby pax given their seats?
- or standby pax will be given seats in C directly?