I don't know about Argerich, Hoffmann, Bergman or Volodos, but this excert from an essay by Brendel on his recordings of Beethoven Piano works seems to suggest otherwise:
"For a player to study autographs and first prints is more than a hobby; in spite of modern Urtext editions, it is frequently a necessity. When does an Urtext edition deserve to be so called? When, basing itself on all existing original sources, it reproduces the text as the composer might have wished to see it, while at the same time discussing mistakes, omissions and doubtful passages in detailed critical notes, quoting all divergent readings, and substantiating editorial decisions. Heinrich Schenker's exemplary edition of the sonatas and the widely esteemed Henle edition come closest to these requirements, without entirely fulfilling them; the edition by Craxton and Tovey regrettably ignores many of Beethoven's articulation markings, while giving phrasing indications of dubious value. The definitive editorial work is still to be done.
Using the early prints as the point of reference, I myself corrected a large part of the variation works, since at the time of recording no tolerably reliable edition of the second volume was yet in existence. In connection with the recording of the miscellaneous pieces (Bagatelles, Rondos, etc.) I began to prepare an Urtext edition of all those pieces I was including in my gramophone series. Certain important documents, however, did not come to my notice until after the recording sessions were over -- as for instance the autograph of the 'Easy Caprice' and the London first editions of some works, the significance of which was not realized until Alan Tyson's book The Authentic English Editions of Beethoven (Faber & Faber) was published in 1963."
JW