Weirdly my experience with interviewing for an SRE role was the reverse: the phone screen was pretty much a straight programming problem (in a Google Doc, ugh) but then one of the on site interviews was very shell programming focused.

I guess to a certain extent it must be the luck of the draw - mass log analysis did crop up in my on-site interview as well, so that seems to be something of a theme, although it was more from a high level systems building POV for me.