Asset ceiling

this question is from ACCA Revising for the September
2020 exam session

A Co manages a DBS for its employees. At 1
January 20X8, the FV of PA were estimated to
be $137 million and the PV of DBO were
$122 million. The asset ceiling has been calculated at $4 million. The discount
rate is 4%. The following are the details of the scheme for the year to 31 December 20X8.

$m
Cash contributions 7
Benefits paid 6
Current service cost 5

At 31 December 20X8, the asset ceiling has been calculated at $11 million.
During the year, there was a scheme curtailment which resulted in a gain on
settlement of $3 million. Immediately after the scheme curtailment the actuary
valued the scheme’s assets as $148 million and the scheme’s liabilities as
$136 million.

in this answer, this was stated “If the effect of the asset ceiling had not been taken into account, there wouldhave been a remeasurement loss of $9.6 million ($21.6million-12million) at 31December 20X8 ”

based on my understanding, asset ceiling will be ignored for curtailment. Why did this answer take asset ceiling into account?