Wendy, 'Herdenkingjaar slavernijverleden' e.g. see https://www.rijksoverheid.nl/onderwerpen/discriminatie-en-racisme/slavernijverleden/herdenkingsjaar-slavernijverleden 2023/2024 is the year that the Dutch government is reminding the population that 150 years ago, the Dutch abolished slavery in their colonies (Suriname and the Caribbean islands). This is more a reflection on the dark aspects of Dutch history than a celebration of the abolishment of slavery by the Dutch.

The presence of the popular character of Zwarte Piet may be seen as evidence that the Dutch have not entirely renounced these dark aspects of their past. See also : https://www.aljazeera.com/features/2019/11/27/zwarte-piet-black-pete-is-dutch-racism-in-full-display

The long history of the figure of Zwarte Piet which goes beyond the racial stereotype is detailed in https://en.wikipedia.org/wiki/Zwarte_Piet

Actually I'm not sure that 'commemorating the history of slavery' is correct - because that would mean they are celebrating the history of slavery. You would rather commemorate the abolishment of slavery. For example we commemorate/honour those who served and sacrificed their lives in war and not war itself.
I think we need 'the end of slavery' : Secretly, Afriyie hoped to have got closer to their goal in the year commemorating the end of / or / abolishment of slavery.

Sounds about right, Wendy. Thanks.

Mark - could this be translated as such: Secretly, Afriyie hoped to have got closer to their goal in the year commemorating the end of slavery.
Commemoration - a ceremony or celebration in which a person or event is celebrated. In the English translation I would suggest using 'the end of slavery', because 'Slavery' itself is not being commemorated.