I am certainly not taking # of movements as a criterium here because there are many 2 movement sonatas by Haydn and earlier Beethoven, in fact op.106 is the first sonata in the typical 4 movements since op.28 (31/3 has 4 movements but no slow movement, 101 has. Like Mahler can use classical form in a rather loose or in a rather strict (like symphony #6, first movement, even with repeat) fashion, so can Beethoven. If you don't perceive such differences between the respective first movements of op.109 or 101 and 106 or 111, I probably cannot say anything to help. Again, an external indication, but probably not accidental that Beethoven writes double bar expo repeats only in these most classicists movements (106,i, 111,i and 101, finale).
Of course, it is still another question if this could or should impact the interpretation and how. I think that the "more strict" movements lend themselves to a more straightforward, less flexible interpretation compared to the more "poetic"/"fantastic" movements.
Gulda is a bit like Toscanini or Leibowitz in the symphonies, fast and straightforward with comparably little flexibility or "highlighting" of contrasts (although as I probably wrote before, I was often surprised that he quite closely follows dynamics, articulations etc. in the score, unlike e.g. Gould who can be very cavalier). The "whole sweep" takes precedence over details, though, and I also think that this does not work equally well everywhere.
