Proposed resolution (October, 2019):

Change 7.6.19 [expr.ass] paragraph 5 as follows:

A simple assignment whose left operand is of a volatile-qualified type is deprecated (D.4 [depr.volatile.type]) unless the (possibly parenthesized) assignment is either a discarded-value expression or appears in an unevaluated context operand.

Notes from the August, 2019 teleconference:

The omission of those operators was intentional; the deprecation is intended only to affect cases where using the result of the operation would result in a subsequent fetch of the value. However, some shortcomings of the existing wording were noted and will be addressed in the resolution.

[Adopted as a DR at the November, 2019 meeting.]

According to 7.6.19 [expr.ass] paragraph 7,

A simple assignment whose left operand is of a volatile -qualified non-class type is deprecated (D.4 [depr.volatile.type]) unless the assignment is either a discarded-value expression or appears in an unevaluated context.

The deprecations of increment, decrement, and compound assignment operators do not, but presumably should, mention unevaluated contexts.