The coronation is in May but I have no idea how the Royals work or positions.It is not about 3 years limit,this is usually for an equerry position, it is something else.
I think after 3 years (in March 2023) he will become another position, better than this, in the Royal Household, which will not be time limited.
I have a feeling about that.
JT might want to go back to his regiment.?? AND spend more time with his family.!?