Duplicate functionality due to added functionality (1st of July)

In July additional functionality will be added to several Microsoft products, in this case I have a customer that currently has Microsoft 365 E3 and a separate Defender for Office 365 Plan 1 license. 

Both licenses will be renewed on the 31st of march, therefore an annual subscription until 30th of march 2027. In July the functionality of de Defender for Office 365 Plan 1 will become part of the Microsoft 365 E3 plan.  Will it be possible to cancel the remaining months of the Defender for Office 365 Plan 1 license or do we need to accommodate for this and change the Defender for Office license to monthly and then cancel the subscription the 1st of July?