To be honest, I did this exercise about two years ago so I'm not certain the following is entirely accurate.
By deselecting the ILS frequencies and preventing reception of the signal the A/P basically gives up and hands control back to you in CWS. As such pitch and roll are yours! The aircraft in all probability will then deviate from the desired ILS profile.
This event should obviously only be momentary. You have a target G/A altitude set in the MCP (higher or lower than present altitude makes no difference). So as soon as you select a new pitch (LVL CHG or V/S) and roll (HDG) mode on the MCP full A/P will re engage and fly in your chosen mode to the selected targets.
If you select TO/GA below 2000' RA single channel approach it's a different game entirely. You then have to start exercising those silky flying skills!
Hope that is of help.