I really don't know what you entirely mean by this, but I always found Schiff to bring out the introverted side of Beethoven's music (when appropriate).
These sonatas aren't particularly suited to weak tone, attacks etc. nor are they remotely depressive. Sure, they're depressed at times, but I think all 3 are celebrations of life rather than dejected writings.
I also don't agree that a lot of the interpretations are particularly extroverted. I've always felt this music is encompassing a lifetime of experience, and I don't think many people who choose to record them make them out to be extraverted. I guess what I mean is, the music is inherently introverted in how sincere and true it is, but that does not translate to the specific qualities you ask about.