I could see the Syntakt superceding the Digitakt if they added sampling.
If it was technically possible, there’d be no reason for them to continue selling the Digitakt since the price points are so close. But who would complain?
The presence of a +Drive does not imply the possibility of sampling. It’s slow, long-term storage.
If it doesn’t have the RAM to hold a decent amount of samples, then it’s not happening.