If we're going to speak about practicalities, rather than just asking what we could do with a near infinite amount of money: Some early DSLRs were semi-based on the chassis of film SLRs - for example the Nikon D100 is generally said to be based on the N80. (It's not literally the same body, but there are similarities.) A company that makes DSLRs today could make film SLRs by re-engineering the body to have film transport instead of an electronic detector. The hard parts of the focal plane shutter, viewing system, body, exposure control, lens interface, etc, are already there.
If one demands a mechanically controlled shutter rather than electronic, then it will become a lot more complicated to create.