Given that the current administration literally issued an executive order claiming that the Smithsonian is bogus, it seems plausible this is just part of an attempt to diminish its stature: https://www.npr.org/2025/03/

Not long ago it would have been hard for me to imagine a president having a vendetta against specific museums, but given how transparent the executive order is, the only question is whether he's petty enough to try to do something like this. Unfortunately I think it's pretty clear from past precedent that this is pretty plausible.