There seem a number of aspects to this story, which apparently relates to the 'one step' vinyl and some or all of the 'original master' series.
First, the reasoning is that studios do not want to let go of the original master tapes, because continual playback and use will, of course, degrade them. The process is therefore that MoFi use a DSD recording, made on a properly setup machine at the relevant studio. This DSD is then returned to analogue at MoFi to cut the master for pressing.
Second, no changes are made in the digital version. AFAIK, this would anyway be difficult if not impossible, as processing in DSD is not the same as in other digital formats.
Third, nobody seems to be denying that the quality is superb. I have a number of 'one step' copies here, and quite a few of the 'original master' series and all of them are superb.
Fourth, and this is where the issue comes in. None of the marketing or anything from MoFi to date has suggested any digital step is involved on their side. The terms 'original master' and 'one step' imply very much the opposite. The graphics on the MoFi website suggest the original master recording is used to cut the first lacquer, which is not really the case. The website text for them states 'mastered from the original analogue master tapes', which is still true, but rather conceals part of the process.
Would it stop me from buying any in future? Probably not, as far as the 'original master' series is concerned. They aren't cheap by any standard, but IMHO the quality of the pressings alone makes them worth the cost. However, I'm not so sure now about the 'one step'. The ones I have are very good indeed, but the cost has always been hard to justify, and now it's even harder.