The absence of the slur in bar 173 in GE1 (→FE) is certainly a mistake. However, it is probably not an oversight, but a "mirror" mistake (reverse sign): instead of placing the slur to the right of the bar line, the engraver printed it on the left-hand side, where it makes no sense in this context (cf. Waltz in C minor Op. 64 no. 2, bars 76-77). In EE the slur was added in the right place, but the one in bar 172 was also preserved. GE2 has a version compliant with A.
Compare the passage in the sources »
category imprint: Differences between sources
issues: EE revisions, Errors in GE, GE revisions, Sign reversal
notation: Slurs