The lateral Flt plan is removed 30 sec after landing (termination of appr phase), as far as I remember, message: DONE.
Automatic deceleration occurs when overflying the DECEL WPT while in NAV or LOC* / LOC mode and below 7'200 ft AGL
(or, of course, manual activation of appr phase). The a/c will only slow to green dot / S / F speed, you have to move flaps manually, of course.
Managed speed YES, but NAV needs at least one FD engaged to remain on.
Cheers Rapide