I'm not aware of any reason it wouldn't operate.

There are/were 2 different routes Buc-Bp-and 1 of these is under long time renovation=out of use. Which means that nearly half of former offer on trains now does not run. Only 1 train has a few cars shunted in Bp to go on to Wien/Vienna. Which means you will still have more choice in making a change in Bp. There are still many refugees from UKR using these trains to reach the west for safe heaven