On Tuesday, the Toronto Maple Leafs signed KHL pending free agent Alexander Barabanov to an NHL contract for the 2020-21 season. According to a Memorandum of Understanding between the KHL and NHL, the contract signing date did not breach any rules. Meaning KHL players on expiring deals, like New York Islanders prospect Ilya Sorokin can sign deals now.
The day after Barabanov signed with the Leafs, Russian outlet RIA Novosti citing the KHL press service indicated that KHL pending free agents are allowed to sign NHL deals so long as they've played the final game of the year, even if it occurs prior to the contract expiring on April 30th.