For equity instruments there will be no further issue concerning impairment (or reversal thereof) as fair value asurement will be used. For debt instruments measured at amortised cost, there is no change to IAS39 regarding the reversal of impairment.
For investments classified at FVTOCI, only dividend income is accounted for in profit or loss, and cumulative other comprehensive income shall not be reclassified to profit or loss subsequently. Therefore, impairment and impairment loss issues do not arise.