No. A Microsoft account and its Xbox profile data cannot be transferred to another Microsoft account.
That means game progress, purchases, subscriptions, balance, and gamertag stay with the Microsoft account they were originally created on. Microsoft personal accounts also cannot be linked, merged, or combined.
The supported option is to keep using the existing Microsoft account and, if needed, change the email address used to sign in by adding a new alias and making it the primary alias. That keeps the same account and preserves the Xbox data.
If the goal is to have everything under a completely separate Microsoft account, that would require starting over on that new account, and the existing Xbox data would not move.