You should declare the date of your (civil) wedding or of your (enforceable) divorce, and any change of name to the fund so that it can record your new personal data.
For a divorce, sharing the LPP/BVG assets between the spouses relates to the assets acquired by each spouse for the duration of the marriage. The assets acquired before the marriage are not shared. The revision of sharing of occupational pensions (that came into force on 1st January 2017) makes provision for sharing when one of the spouses receives a disability pension or a retirement pension of the 2nd pillar. As regards your LPP/BVG assets, the fund has to make a calculation in order to determine the vested benefits acquired during your marriage. To that end, we will need to know the date of the (civil) wedding, and the date of filing of the petition for divorce with the court.