I’m a random person but my understanding was that legally the funds belong to the Biden/Harris campaign, now owned by Harris. I think moving that money between campaign funds is not permitted. Maybe some unprecedented swap where Harris remains VP would work.

Edit: i actually researched this, LegalEagle has a good video on it.

In short donations to DNC are safe, but the campaign committee for B/H would need to go into a super PAC and would face litigation risks