The last part of the first subparagraph of Article 500 states that "The adjustment referred to in the first subparagraph [(i.e. Adjustment for massive disposals)] may only be carried out until 28 June 2022 and its effects may last for as long as the corresponding exposures are included in the institution's own LGD estimates". 

How is 28 June 2022 to be interpreted? Is it a repetition of point (b) of subparagraph 1 (i.e. "the dates of the disposals of defaulted exposures are after 23 November 2016 but not later than 28 June 2022") or it represents the cut-off date by which the adjustment can be estimated?

The question arises because it is not clear if the date indicated (i.e. 28 June 2022) identifies the last date in which a massive disposal can take place and be considerated in the adjustment or indicates the last date in which the adjustment can be computed.

Under the first subparagraph of Article 500(1) of Regulation (EU) No 575/2013 (CRR) an institution is permitted to adjust its LGD estimates for massive disposals in derogation of point (a) of Article 181(1) CRR as soon as it meets the three conditions listed in the first sub-paragraph. The second subparagraph constrains the institution’s discretion beyond the three conditions in the first subparagraph by additionally requiring that the adjustment may also only be carried out until 28 June 2022, irrespective of the date of the disposals.
However, this does not mean that all existing adjustments in accordance with Article 500 CRR (and therefore carried out until 28 June 2022) may no longer be subject to change after 28 June 2022.