I don’t speak for the DT people, but I do not think that it works this way. “redirect to a cloud service” is of course sufficiently vague to make it sound plausible. But think about the details: DT would have to write this “cloud service” if they were to access their data stored on this cloud provider’s servers. DT is Mac software, not Linux or Windows. Even DT’s own web server runs only on a Mac, because (I suppose) it is basically exposing their data through their own software to a webserver. The webserver is most probably just a standard one, like nginx or Apache.
Now, I’m not aware of any relevant cloud service provider offering MacOS virtual machines. If DT needs MacOS to run, how would they do that in “the cloud” without MacOS? Basically, they’d have to write their software for Windows or Linux. Which they are obviously not going to do.
It is not about a “webinterface that is able to connect to data stored at a certain” cloud provider. That would be nearly trivial. But you want DT’s functionality, not simply a view on your data. Otherwise, you could just make your data available via SMB or something similar and browse it. No need even for a web server.